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

The annotations already carry readOnlyHint=true, and the description is consistent with that — it 'renvoie' (returns) rather than mutates. Beyond the annotations, it discloses the quota cost ('Coût : 1 unité de quota'), which is a genuine behavioral trait not present in structured data. It does not contradict the read-only hint.

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 a single dense sentence that front-loads the core action before listing return fields. The field enumeration is long but earns its place because there is no output schema, so it is the agent's only source for expected return content. Slightly sprawling, but nothing is filler.

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 carries the full burden of explaining return values, and it does so exhaustively: ~13 fields, document/source links, the public fiche link, input provenance, and cost. For a single-parameter read-only lookup, nothing an agent needs 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 coverage is 100%: the id parameter already has a full description, type, range, and example in the schema. The tool description essentially repeats the same provenance info ('champ id renvoyé par propecto_rechercher_marches') without adding new semantic value beyond the schema, so the baseline of 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?

The description opens with a specific verb+resource pair, "Renvoie le détail complet d'un avis de marché public à partir de son identifiant numérique Propecto," and then enumerates the full set of returned fields (intitulé, acheteur, CPV, montant, dates, attributaire, documents, liens). It also ties itself to propecto_rechercher_marches via the id provenance, distinguishing the detail-fetch role from the search role.

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?

Usage context is implied rather than stated: the id is explicitly sourced from propecto_rechercher_marches results, and the cost disclosure ('Coût : 1 unité de quota') adds a practical consideration. However, the description never names sibling alternatives (propecto_societe, propecto_finances, etc.) or gives when-not-to-use exclusions, so the agent must infer the choice.

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