zero_search_results_keywords

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

Annotations already indicate read-only, idempotent, non-destructive behavior. The description adds behavioral details: no aggregation, pagination ignored, and raw data returned. This goes beyond the annotations by clarifying how the tool operates on the data, though it does not cover rate limits or error handling.

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 concise, front-loaded with purpose and output format, and includes only essential details. The URL to the full spec is efficient and avoids redundancy. No unnecessary words.

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 tool's simplicity (3 params, read-only, no output schema), the description covers purpose, output, filters, and behavior (no aggregation, pagination ignored). It provides a link to the full spec for completeness. Could mention typical use cases or limitations, but is adequate for agent invocation.

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 coverage is 100%, so the baseline is 3. The description mentions startDate/endDate as filters and notes that pagination is ignored, but does not add new semantic meaning beyond what the schema already provides. The schema already describes the sourceKey restriction clearly.

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 it returns keywords with zero search results for a single source, explicitly for SEO gap analysis, and specifies the output format as `{details:[{searchKeyword, count}]}` with count indicating frequency. This distinguishes it from other keyword tools like search_keywords_by_source, which return all keywords, and from the export sibling.

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 implies usage for identifying missing keywords, but does not explicitly state when to use this tool vs alternatives like search_keywords_by_source or the export variant. It does provide useful guidance that only `marketplace` is supported and that `embedded-marketplace` will be rejected, but lacks general usage boundaries.

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