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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint. The description adds crucial behavioral context beyond these: it reads the board's index rather than the employer's live site, and it is explicitly a weaker test than get_job. This informs the agent of the tool's limitations and the need to check the `basis` field, which annotations alone cannot convey.

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 well-structured and front-loaded with the core purpose, but it is slightly verbose. The phrase 'instead of spending a metered get_job per posting' is valuable guidance but could be integrated more compactly. Overall, it earns its place with no fluff, but a tighter phrasing would push it to 5.

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 covers the return format (open:{id:boolean} plus closed ids and basis), the caveat about basis, the prerequisite key/sign-in, and the tool's relationship to get_job. With an output schema present, it still provides essential behavioral context. Nothing an agent needs to decide when and how to call it correctly is missing.

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?

The input schema already provides a description for the `ids` parameter (from search_jobs, max 200, notChecked behavior) and has 100% schema description coverage. The description restates the 200-id limit but adds no new semantic detail beyond what the schema specifies. Per the rubric, with high schema coverage, baseline 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 opens with a direct question and a clear statement of what the tool does: 'Are these postings still on the board? Answers up to 200 ids in one call'. It identifies the resource (job postings) and the action (checking open status), and explicitly contrasts with the sibling get_job, making differentiation unambiguous.

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 provides explicit when-to-use guidance: 'the tool for re-verifying a saved shortlist before acting on it, instead of spending a metered get_job per posting.' It also flags a key caution: 'it is a weaker test than get_job's — read `basis` before reporting a posting as live to a person,' and states the prerequisite 'Needs a key or a sign-in.' This is thorough and actionable.

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