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

Annotations only declare this is a non-readonly, non-destructive, closed-world write; the description adds the failure contract ('REFUSED with an error, nothing written, if the id already exists') and the full default-filling behavior for omitted fields, which annotations cannot convey. It stops short of mentioning permissions or auth requirements for the write itself, so not quite 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?

Front-loaded with the core action and the entity definition, then failure modes, then defaults, then sibling routing — a logical order with no filler sentences. It is dense with long parentheticals, but every clause carries operative information.

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 12-parameter creation tool with no output schema, the description covers the required fields, the uniqueness/refusal behavior, all defaults for omitted fields, and the lifecycle relationship to assign_person and update_person. An agent has everything needed to call it correctly on the first attempt.

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%, so the baseline is 3, but the description adds value by enumerating the concrete default values (initials derived from name, role empty, colour '#5b9eff', network 'core', category 'executant', level 'Intermédiaire', no tags) that the schema mostly does not state. That is meaningful semantics beyond the field-level descriptions, though it repeats the kebab-case id constraint the schema already carries.

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 and resource ('Creates a person') and immediately defines what a person is in this domain ('a member of the project's network: partner, executive, contributor…'), which distinguishes it from update_person, search_people and assign_person by naming each of those siblings explicitly.

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?

Gives explicit routing: use search_people to check existence, update_person to modify, and calling this tool with a new id deliberately creates a second separate person. It also states the when-not case implicitly via the refusal rule, leaving almost nothing to inference.

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