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

Annotations already establish readOnly and non-destructive, but the description adds value beyond them: it discloses the cost/latency profile ('Free — reads stored Search Console data, no external call') and explains what an empty result means operationally. That is real behavioral context the annotations do not 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?

Three tight sentences, front-loaded with the purpose, then cost, then usage and the empty-state remedy. No sentence is wasted and nothing is buried.

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 does describe the shape of results (page that ranks plus position) and handles the empty case plus its prerequisite. It leaves pagination/limit behavior implicit, but the essential call-time knowledge is present.

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% for both parameters (limit, site_id), so the schema carries the parameter burden. The description adds nothing about limit syntax or defaults, which is fine given the baseline for fully documented schemas.

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 with sharp scope: keywords the site 'ALREADY ranks for but is not tracking,' and even names the return fields (the ranking page and its position). An agent can distinguish this from get_gsc_queries or get_live_keyword_ideas without opening the 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?

Gives explicit behavioral direction ('Use this instead of asking the user to think up keywords') and a concrete recovery path for the empty case (run sync_search_console first). It stops short of naming sibling keyword-generation tools as alternatives, so it's clear context without full alternative routing.

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