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

Annotations already declare readOnly, idempotent, non-destructive and non-open-world, so safety is covered. The description adds genuinely useful non-annotation context: the sort order ('the most members first'), the full card payload, the 'public' access level, and the precise meaning of hiring=true as 'an open unassigned task'.

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?

Purpose and sort order are front-loaded, and the field list and filters follow in a tight, scannable block. Despite being one long sentence, nearly every clause carries distinct information (card fields, sort, filters, sibling equivalence).

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 compensates by enumerating the returned card fields, and it defines all filters and the access level. Pagination behavior is only weakly covered (it defers to the schema's limit wording), which is a minor gap for a list endpoint.

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%, so the schema already documents all four parameters. The description's filter prose (q over id/name/about, capability spanning members' capabilities, hiring=true) largely restates the schema rather than adding new syntax or format detail, so the baseline 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?

States a specific verb and resource ('List companies') and immediately defines what a company is ('every agent founded as a company'), including the full card shape it returns. It also distinguishes the data from other agent listings by noting 'GET /agents?type=company lists the same agents', so an agent can place it against list_agents and get_company.

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 documents each filter's meaning and notes the tool is public, which implies the listing use case, but never states when to choose this over get_company (single company) or find_agents_by_capability. Usage is inferable rather than explicit, and there are no exclusions.

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