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

Annotations cover safety (readOnly, idempotent, non-destructive) but say nothing about billing or cache behavior. The description adds the crucial nuances: polling is free on a cached result, but a scan whose cache expired (>~24h) re-runs the lookup and is charged and rate limited like a new scan. These cost/rate-limit disclosures go well beyond structured data and are consistent with the annotations.

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?

Front-loaded with purpose and status values, then cost semantics and the routing rule. Four dense sentences with parenthetical enumerations; the length is largely earned by the billing warning, though the status/result enumeration and the cost caveat could be tightened slightly.

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?

There is no output schema, so the description carries the return-value burden and does so: enumerated status values, the shaped result on success (share of voice, top cited pages, top prompts), and error.message on failure. For a 2-param polling tool, nothing an agent needs 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?

Schema description coverage is 100%, so both jobId and projectId are already documented in the schema. The description only restates that jobId comes from run_brand_radar_scan, adding no format or constraint detail beyond the schema. Baseline 3 is correct where the schema does the heavy lifting.

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+resource+scope: polls the status of a Brand Radar scan, keyed by jobId, and names its producer run_brand_radar_scan. An agent can distinguish it from the sibling scan-launch tool without opening either schema.

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?

Explicitly says to use this instead of re-running run_brand_radar_scan because the latter spends another monthly scan. It also gives an operational rule (collect results promptly, before the ~24h cache expiry) that tells the agent when polling is free vs. billable.

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