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

Annotations already declare readOnlyHint=true, so safety is covered. The description adds real behavioral value beyond that: it enumerates the returned payload (day, register line, receipt address) and, importantly, defines the empty-result case ('Aucun dépôt : le document n'a pas été daté par ce service'), which prevents an agent from misreading a null as an error. It omits auth/rate-limit details, so not a 5.

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 tight sentences with no filler: the first states what is returned, the second handles the empty case. The primary behaviour is front-loaded, and the minimal length matches a one-parameter lookup tool.

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 simple read-only lookup with one fully documented parameter, an existing readOnlyHint annotation, and no output schema, the description covers the essentials: what comes back and what an empty result means. The only gap is not pointing to the sibling used to create a date, which would round out the workflow.

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?

There is a single parameter, and schema description coverage is 100%: the schema already specifies '^[0-9a-fA-F]{64}$' and '64 caractères hexadécimaux'. The description only repeats 'empreinte SHA-256' without adding format, casing, or sourcing guidance beyond the schema. Baseline 3 is appropriate when the schema carries the parameter detail.

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 gives a specific verb-and-resource: it returns every 'dépôt' (deposit/anchor) recorded for a given SHA-256 fingerprint, plus the fields returned (day, register line, receipt address). Together with the title 'Trouver les dates d'un document', an agent can tell this is the read/lookup counterpart to the sibling dater_empreinte. It stops short of explicitly naming that sibling, so it is clear but not fully differentiated.

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 is only implied: query a hash to find whether/how it was dated. There is no explicit statement of when to use this versus dater_empreinte (to create a date) or dater_url (for URLs), nor any prerequisite such as performing the dating first. The implied context is sufficient to act but not to choose confidently among siblings.

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