Common mistakes in a web agency brief

This technical analysis identifies common mistakes in a brief for web agency and offers concrete ways to ensure the success of the project from the drafting of the initial document.

Identify errors related to objectives and positioning

The quality of a web project depends first of all on the clarity of the objectives. A Forgetting clear objectives This blocks the agency's ability to deliver a measurable and tailored strategy. Without defined objectives (conversion, awareness, lead generation, customer support), technical and editorial choices become arbitrary and costly.

Take the example of a fictitious SME, AtelierNova, which wants to modernize its e-commerce site: if the brief simply states "improve sales," the agency won't know whether the objective is to reduce the shopping cart abandonment rate, increase the average shopping cart, or develop the international market. The most common consequence is the multiplication of unnecessary iterations and the waste of time on non-priority features.

• Signs of a poorly defined brief: generic objectives, lack of indicators (KPIs), no time horizon.
• Practical effects: poor prioritization of features, misdirected budget, inadequate reporting.
• Solutions: define 3 priority KPIs and a deadline, segment the short/medium/long term objectives.

When auditing a brief, the agency must ask framing questions: what is the expected sales volume? what is the target conversion rate? what is the share of the organic traffic expected after 6 months? These elements allow you to transform vague wishes into operational objectives.

Concrete examples of well-formulated objectives:

1. Increase conversion rate from 1.2% to 1.8% within 6 months through purchase funnel optimization.
2. Reduce the bounce rate of product pages to 40% in 4 months through UX redesign and enriched content.
3. Get 30% of traffic via organic SEO within 12 months of launch.

To facilitate implementation, it is recommended to include in the brief a summary table of objectives with KPIs, metrics, numerical objective and deadline. Such a table serves as a performance contract and a basis for post-delivery monitoring.

Objective	KPI	Current value	Target value	Due date
E-commerce conversion	Conversion rates	1,2%	1,8%	6 months
SEO traffic	% of organic traffic	18%	30%	12 months

Quick checklist to fix a Forgetting clear objectives in a brief:

• Write 3 SMART objectives with KPIs.
• Prioritize in order of impact and feasibility.
• Add a “success assumptions” section (traffic, conversion rate, budget).

To go further, technical resources like SEO guides or measurement tools can help clarify KPIs. For example, the article on 10 tips to boost SEO provides insights for aligning objectives and indicators. Final insight: a brief focused on measurable objectives significantly reduces the risk of a gap between expectations and deliverables.

Avoid budgeting and planning mistakes

A brief that does not specify a budget generates misunderstandings and quotes that are too broad or too optimistic. Lack of defined budget often pushes the agency to propose generic solutions or to multiply the costing phases, which lengthens the deadlines and costs more in the long term.

Use case: AtelierNova consults with three agencies without specifying a budget range. Proposals range from a low-cost one-page site to a six-figure custom platform. The result: a longer decision-making time and client frustration. A communicated budget, even as a range, helps align ambition and deliverable.

• Why specify a budget? It helps guide technological choices and define the minimum viable scope (MVP).
• How to estimate? Use internal benchmarks, agency feedback, and industry guides.
• Practical tips: allow a margin of 15-25% for unforeseen events and technical developments.

Visit Unrealistic deadlines are often linked to a lack of knowledge of the development process. Typical stages include scoping, mockup, development, testing, acceptance testing, and deployment. Each stage must be dated and accompanied by a validation phase. Without this breakdown, customer feedback is delayed and sprints pile up.

Operational advice:

1. Provide a decision-making schedule with key dates (choice of agency, receipt of deliverables, acceptance phases).
2. Plan for intermediate validation milestones to limit extended return cycles.
3. Allocate time for content migration and training of internal teams.

Among the recommended management tools, Trello and other kanban tools help to synchronize client and agency teams; a practical guide is available via Trello: User Guide. Integrating an automation device for repetitive tasks reduces the project load, as described in the article on AI automation for web agencies.

Checklist to avoid Lack of defined budget and Unrealistic deadlines :

• Indicate a budget range and the maximum budget tolerated.
• Plan milestones and validation phases in the brief.
• Specify client-side responsibilities (content provision, validations, access).

Final insight: A realistic budget and schedule from the brief reduces the risk of financial and time drift, and facilitates the comparison of agency proposals.

Define the target, deliverables and expected content

Lack of knowledge of the target leads to theLack of specific target in the brief, which compromises the effectiveness of UX, design and message choices. Detailing personas (age, behavior, channels consumed, objections) helps guide the user journey and content hierarchy.

Example: AtelierNova targets two segments: architects (B2B) and individuals. If the brief doesn't specify this, the agency risks designing a hybrid interface that doesn't satisfy either segment. The solution is to provide persona sheets and usage scenarios.

• Elements to include for each persona: objectives, obstacles, digital habits, information channels.
• Why it's crucial: Guides navigation, editorial tone, and CTAs.
• Useful tools: customer surveys, existing analytics, user interviews.

Visit Poor definition of deliverables is another common mistake. A brief must precisely list the expected deliverables: mockups (desktop/mobile), UI kit, source files, test environment, technical documentation, CMS access, and acceptance criteria. Without this granularity, the delivery may be incomplete or ambiguous.

Typical list of deliverables to be specified:

1. High fidelity mockups for desktop and mobile.
2. Graphic kit (fonts, colors, icons) and source files (Sketch/Figma).
3. Technical documentation and operating guide for the CMS.
4. Test plan and acceptance criteria.

The problem of Content not provided is critical: missing photos, texts, product sheets, or videos delay developments. The brief must specify delivery responsibilities and expected formats. A clause that sets deadlines for content submission and provides for automatic reminders avoids blockages.

Recommended procedure:

• Include a table of contents with owner, format, and delivery date.
• Plan a phase of generation or adaptation of content by the agency if the client requests it (with separate budget).
• Use collaborative tools to centralize assets (e.g. Drive, DAM platforms).

To optimize natural referencing from the design stage, explicitly mention the Failure to consider SEO as a point to correct: integrating an SEO strategy, sitemap, and redirection plan is essential. Additional resources such as the guide on the sitemap and SEO plugins help to frame these aspects.

Element class	Manager	Format	Deadline
Product sheets	Customer	CSV + 2000px images	D-30 before dev
Marketing content	Agency/Client	DOCX, MD	D-20

Final Insight: Describing the target, defining deliverables and securing content production in the brief avoids operational blockages and ensures that the final product will meet user needs.

Specify technical constraints and SEO

Visit Omission of technical constraints in a brief is often a source of rework. It is necessary to specify the technical ecosystem (hosting, preferred stack, PHP/Node versions, compatibility constraints, CRM/ERP integrations, existing APIs). Without this information, the agency may propose a solution incompatible with the existing infrastructure.

For AtelierNova, the existence of a legacy ERP imposes API and inventory synchronization constraints. The brief must therefore detail the APIs, data schemas, synchronization frequencies, and security constraints.

• Technical points to include: stack, versions, expected architectures, hosting constraints.
• Integrations: lists of tools to connect, data flows and touchpoints.
• Security: GDPR requirements, SSO authentication, encryption of sensitive data.

Lack of attention to SEO from the technical phase can turn an optimized site into an SEO nightmare. Failure to consider SEO includes the absence of a sitemap, canonical URLs, a redirect plan, and on-page optimizations. It is recommended to include in the brief:

1. SEO objectives (priority keywords, target pages).
2. Technical SEO constraints (speed, markup, URL structure).
3. SEO deliverables (redirection plan, sitemap.xml file, meta tags, internal networking).

Resources to inspire these elements can be found in specialist guides, such as the semantic cocoon guide or the backlink strategies described on Dualmedia.

Another critical point: performance and security. In 2025, web and mobile security requirements have become more stringent; it is relevant to refer to lists of best practices such as Cloud security practices 2025 and threats and protections 2024 to calibrate needs.

• Include mandatory safety rules and performance standards.
• Specify compliance constraints (GDPR, log storage, restricted access).
• Plan for penetration testing and post-delivery audits.

Final Insight: A technical brief that documents all the constraints helps avoid incompatibilities and secure the operation of the site or application.

Manage changes, governance and documentation

Projects often fail because of Frequent changes without documentationGovernance must be defined in the brief: who validates, who manages the deliverables, what are the escalation points in the event of conflict. Without this, changes become sources of instability and budget overruns.

AtelierNova experienced repeated back-and-forth discussions on the structure of the product page because the brief didn't specify a validation process. Implementing a change log and a governance charter allows them to track all decisions and assess the financial and time impact of each modification.

• Governance rules: project committee, validation managers, response SLA.
• Change management: request procedure, impact assessment, formal approval.
• Documentation: deliverables, technical READMEs, user guides, version history.

Visit Brief too vague fuels most of these deviations. An effective brief includes: scope, explicit exclusions, acceptance criteria, and a technical annex. It is advisable to attach visual examples (references, mockups) and to use a standard template to standardize briefs within the organization.

Examples of governance elements to be inserted:

1. List of decision makers with authority levels.
2. Deliverable approval process and response times.
3. Monitoring methods (weekly reporting, progress points, shared backlog).

Finally, contractualization: the brief acts as the first version of the specifications. It is a reference document in the event of a dispute, accompanied by a schedule and a contract specifying delivery conditions and possible penalties. For more information on drafting specifications, consult this guide.

Final insight: Defining governance and documenting each change transforms the brief from a simple starting document into a contractual and operational tool for the duration of the project.

Why is a brief for a web agency important?

A web agency brief is essential for defining objectives and aligning stakeholders. It serves as a technical and marketing roadmap, sets KPIs, and facilitates the tracking of deliverables.

How to write an effective web agency brief?

An effective web agency brief begins with SMART objectives and a clear description of personas. It also details the scope, deliverables, budget, and timeline to avoid ambiguity.

What are the benefits of a well-structured web agency brief?

A well-structured web agency brief reduces the risk of overruns, improves the quality of deliverables, and accelerates production. It also facilitates post-launch performance measurement.

Is the web agency brief suitable for a complete website redesign?

Yes, a web agency brief is suitable for a complete redesign because it allows you to formalize technical constraints, SEO objectives, and the migration timeline. It serves as the basis for the specifications.

Why include the budget in a web agency brief?

Indicating the budget in a web agency brief helps frame technical and creative proposals. This avoids misaligned bids and helps define a realistic MVP.

How to integrate SEO into a web agency brief?

Integrating SEO into a web agency brief involves listing target keywords, SEO objectives, and technical deliverables (sitemap, redirects, tags). This guides the agency from the design stage.

What deliverables should a web agency brief contain?

A brief for a web agency should list desktop/mobile mockups, a UI kit, technical documentation, a test plan, and acceptance criteria. These elements clarify expectations and facilitate acceptance testing.

Should the brief for a web agency specify technical constraints?

Yes, the brief for a web agency must specify the technical constraints (stack, integrations, hosting) to avoid incompatible solutions and anticipate technical risks.

What to do if the content is not provided in the web agency brief?

If the content is not provided in the web agency brief, plan a content production phase or clearly define responsibilities and expected formats to avoid delays.

How to manage frequent changes in a web agency brief?

Managing frequent changes in a web agency brief requires a change log, a formal request procedure and an impact assessment before validation to control costs and deadlines.

Should the web agency brief include KPIs?

Yes, the web agency brief must include clear KPIs to measure success (traffic, conversion, load time). KPIs help you objectify results and guide optimizations.

Why formalize governance in the brief for a web agency?

Formalizing governance in the web agency brief helps clarify roles, validation deadlines and decision-makers, avoiding blockages during iterations.

How to include security and compliance in a web agency brief?

Including security and compliance in the web agency brief involves listing GDPR requirements, authentication protocols, and required audits, ensuring the robustness and compliance of the project.