Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly, idempotent, non-destructive and closed-world. Beyond that, the description adds genuinely useful behavior: the search returns only document metadata (id, titre, adresse) rather than full content, so a follow-up fetch is required — a two-step workflow the annotations do not convey. It stops short of disclosing result counts or ranking/fuzzy-match behavior.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences, no filler: scope and return shape come first, then the routing/next-step guidance. Every clause carries actionable information for an agent.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a single-parameter search with a full output schema, the description covers the domain it searches, the shape of what is returned, and the follow-up step. Nothing needed to invoke it correctly is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100% and the schema already specifies the query format, length bounds and the French-language preference with an example. The description adds nothing about the single parameter beyond that, so the baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb ("cherche") and resource ("le contenu officiel de flytel.fr") and scopes the resource with concrete content types (forfaits, guides, FAQ). It also names what is returned (id, titre, adresse), which lets an agent distinguish it from fetch and the pricing siblings without opening a schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly routes the agent: use fetch to read a document, and prefer get_plan / calculate_monthly_price / check_usage_compatibility when a precise price or inclusion is needed. That is real alternative-naming, but it doesn't cover the remaining siblings (compare_plans, find_best_plan, list_plans, flytel_tarifs_pays) nor state an explicit when-not-to-use condition.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.