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

Annotations already declare readOnlyHint=true and destructiveHint=false, but the description adds genuinely new context: "sans compte" (no authentication required) and the return shape ("rend les passages utiles avec leur source"). It does not say what happens when the documentation has no matching passage, which is the main remaining behavioral gap.

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, zero filler. The search scope is front-loaded and the usage condition plus read-only/no-account note follow immediately, so an agent can decide and act from the first clause.

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, annotation-covered retrieval tool with no output schema, this covers what it searches, why to use it, and that it needs no account. The only omission is fallback behavior when no relevant passage exists.

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 coverage is 100% and the single `question` parameter already carries a description, a maxLength of 300 and an example, so the schema does the heavy lifting. The description's topic list marginally hints at the kind of question to ask, but adds no syntax or format guidance beyond the schema.

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 ("la documentation officielle de Tchin") and enumerates the covered topics (frais, délais, API, sécurité...). The scope clause "Pour les questions sur le fonctionnement de Tchin" cleanly separates it from the transactional/account siblings (mon_compte, mes_transactions, creer_lien_paiement).

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?

"Pour les questions sur le fonctionnement de Tchin" gives a clear trigger condition, and the documentation-search framing implicitly excludes account-state queries handled by siblings. It never explicitly names an alternative or states when not to use it, so it stops short of a 5.

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