gsc_keyword_expand

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

Annotations already mark readOnlyHint and idempotentHint. The description adds critical behavioral context: explains the 'footprint verdict' and confidence band, and crucially discloses that GSC hides ~75% of impressions, making results hypothetical. No contradictions 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?

Concise at 7 sentences, front-loaded with purpose, each sentence adds necessary detail without redundancy. Well-structured for quick comprehension.

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 lack of output schema, the description adequately explains the return (footprint verdict and confidence band) and addresses the hypothetical nature of results. Covers all key aspects of use.

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 covers 100% of parameters, but the description adds value by explaining how to obtain candidates ('brainstorm from winning queries') and for 'days' adds 'wider = more footprint visible'. This enriches understanding beyond the schema.

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 uses a specific verb ('Ground... candidates to find net-new terms') and clearly distinguishes from sibling tools like gsc_top_queries by recommending it as a prerequisite. It leaves no ambiguity about the tool's function.

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 instructs the user to brainstorm candidates from gsc_top_queries first, providing clear context. However, it does not explicitly mention when to avoid this tool in favor of other siblings like gsc_query_gaps, though the workflow is implied.

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