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

Annotations already declare read-only, idempotent, and non-destructive behavior, so the bar is lowered. The description adds useful behavioral context: it explains the query syntax, the specific fields searched, and the returned fields (SIREN, name, status, NAF, etc.), which go beyond the schema and annotations. No contradictions.

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 compact and well-structured: it opens with the core purpose, then details filter fields and operators, lists return fields, and ends with a pointer to the sibling tool. Every sentence earns its place; no 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 an output schema present, return values are defined. The description covers query capabilities, filter options, operators, and the alternative tool for more detail. Pagination is handled by the schema (max, offset). It is fully adequate for an agent to call this tool correctly.

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% – every parameter (q, max, offset) already has a detailed description with examples. The description reinforces the q syntax and field names but does not add meaning beyond the schema, so the baseline of 3 is appropriate.

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 states a specific action (search) on a defined resource (French legal units in INSEE Sirene) and enumerates the filterable fields (name, NAF code, status, legal category) with examples. It differentiates from the sibling insee.company.by_siren by noting that tool retrieves full details, and implicitly separates it from insee.establishment.search by focusing on legal units.

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?

It provides explicit guidance on query construction (Lucene-style, AND/OR operators) and points to insee.company.by_siren for full details, making the distinction clear. It does not explicitly mention when to use establishment.search instead, but the focus on legal units vs. establishments is implied, leaving a minor gap.

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