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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered; the description adds value with the return-shape equivalence ('same object as GET /api/v1/providers/{slug}') and the language default behavior. It stops short of describing error cases when no fiche matches.

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?

Three tight sentences: the primary operation and identifier forms lead, then the return-shape note, then the language default. No filler or redundancy.

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?

With no output schema, the description compensates by naming the equivalent REST endpoint so the agent can infer the return object, and it covers the lang default. Only the no-match/error behavior is left unstated for this simple read tool.

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%, so both parameters are already documented in the schema. The description only reinforces that lang defaults to French and gives an alias example ('ga'), adding marginal meaning beyond the structured fields. Baseline 3.

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 (look up) and resource (one StackLégal provider fiche), and explicitly enumerates the three accepted identifier forms (canonical slug, alias, exact catalog name). This clearly separates it from the sibling list_providers.

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?

Implies single-record retrieval versus listing, and warns that a name match is not a legal qualification, but never explicitly routes to alternatives (e.g. 'use list_providers to enumerate'). Usage context is implied rather than stated.

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