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

Annotations already declare readOnly, openWorld, idempotent, and non-destructive behavior. The description adds valuable behavioral context beyond these: no credit is debited, the total is exact and not capped, and Companies returns an additional `establishmentsTotal` for points of sale. This gives the agent a fuller model of side effects and outputs.

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 dense but well-structured, with a front-loaded summary of behavior, a special note for Companies, and bullet-like filter syntax rules. Every sentence earns its place by conveying critical usage or cost information without 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?

The description is complete for a counting tool: it covers purpose, cost, output semantics, filter structure, kind-specific differences, and points to sibling descriptions for the full key list. The presence of an output schema means return values need not be repeated here. An agent has enough to call this tool correctly in context.

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?

Although the schema covers both parameters, the schema's description of `filters` is generic, pointing to sibling tools. The tool description compensates by explaining concrete filter syntax: include/exclude objects with OR/NOT semantics, AND between different filters, numeric range objects for People, and `_min`/`_max` fields for Companies. This adds substantial meaning beyond the schema.

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 precise purpose: 'Renvoie le NOMBRE TOTAL de résultats pour des filtres.' It clearly distinguishes this tool from search/export siblings by emphasizing that it returns only a count, is free, and is exact. The title 'Compter sans extraire' reinforces the differentiation.

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?

The description explicitly instructs when to use it: 'À appeler TOUJOURS en premier.' It contrasts with search/export tools by noting they cost 1 credit per record, making the alternative usage condition clear. It also references basile_search_people / basile_search_companies for detailed filter keys, further guiding tool selection.

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