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

Annotations already cover readOnlyHint=true and destructiveHint=false, so the safety profile is established. The description adds value beyond annotations by disclosing the full return payload and the notable behavior that it 'returns the public URL to cite', which agents need for downstream usage.

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?

The description is well-ordered: return payload first, then URL behavior, then id sourcing. The French/English duplication doubles length, but each sentence is dense and information-bearing, so the structure earns its place.

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 one-parameter, read-only fetch with no output schema, the description's detailed field list acts as the return contract and is largely sufficient. The only gaps are edge-case behaviors such as handling of invalid ids or empty results, which are minor for a simple lookup 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 coverage is 100% — the id property is documented as 'Numeric certification id' — so the baseline is 3. The description adds genuine meaning by telling the agent where the id comes from (search_certifications or get_job_pathways), which the schema alone does not convey.

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 the resource precisely ('Full record of a diploma or certification') and enumerates the returned fields: title, RNCP/RS codes, type, exit level, access routes, average training price, target jobs, and programme count. It also names the public URL behavior and the two siblings that supply the id (search_certifications, get_job_pathways), which distinguishes it from search and training-record tools.

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 caller: 'Get the id from search_certifications or get_job_pathways', which implies the correct lookup-then-fetch workflow before calling this tool. It does not explicitly state when not to use it versus alternatives like get_training, but the certification-specific field list makes the resource boundary reasonably clear.

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