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

The description goes beyond the annotations (readOnlyHint and openWorldHint) by stating it is free and does not charge credits, and that listing never triggers a sorting pass so it cannot bill. It also adds that another account's id returns a 404, not 403 (though this is in the schema, the description reinforces the behavioral expectations). No contradiction with 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?

The description is two sentences, tightly packed with essential information: what is returned, how it relates to another tool, and the cost/side-effect behavior. No fluff, front-loads the core purpose, and every clause adds value.

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?

Given the single parameter and no output schema, the description adequately outlines the return content (buckets with id, label, rule, count; plus unsorted and pending counts). It also explains the linkage to get_keyword_results. It could specify the exact return structure (array vs object) but that is not essential for an agent to call it correctly.

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 single parameter 'id' is fully described in the schema: 'Keyword id, from list_keywords. Another account's id is a 404, never a 403.' The main description does not add additional parameter semantics, so it relies on the schema, which is complete (100% coverage). Baseline of 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 clearly states the tool lists the buckets a keyword sorts its mentions into, enumerating the fields (id, label, plain-language rule, count) and adding unsorted/pending counts. It also differentiates its purpose from get_keyword_results by explaining the relationship of the ids and labels, which helps an agent understand what this tool is for.

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 explains how the output is used: the ids are passed as bucket= to get_keyword_results, and the labels explain the meaning of ids in that output. It also notes that the tool is free and never triggers a sorting pass, so it can be called without cost concerns. It doesn't explicitly contrast with sibling tools like keyword_bucket_manage, but the read-only listing intent is clear.

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