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

Beyond the readOnly/idempotent annotations, it discloses scope rules (LinkedIn-excluded, freshness-floored), the semantic meaning of coverage_status values, and the empty-string API key fallback returning a signup link instead of an auth error — real behavioral context annotations cannot carry.

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?

Dense and front-loaded — the WHEN clause leads, followed by scope, parameter guidance, examples, and the sibling pointer. Every sentence earns its place, though the packed parentheticals and dual examples make it longer than strictly necessary.

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?

No output schema exists, yet the description conveys return semantics via worked examples (is_hiring true with open_req_count 7 and coverage_status 'ats_direct_hit'; false with 'no_ats_signal'). An agent has everything needed to call and interpret it.

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 only 33%, so the description must compensate: it does so for company_id (integer id from an earlier result, not a name or domain, with a concrete example) and plane_api_key (empty string triggers signup link). idempotency_key is left unexplained in both schema and description.

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 precise intent — qualify whether a held company is hiring — and names itself as the 'cheap gate before spending a richer call.' It explicitly distinguishes from the sibling who_is_hiring_for, so the agent can route without opening schemas.

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 an explicit trigger ('WHEN an agent already holds a company'), contrasts with the discovery sibling ('To find companies in the first place, use who_is_hiring_for'), and adds both the no-key workaround and a warning not to treat 'no_ats_signal' as a negative. When/when-not/alternatives are all present.

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