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

Beyond the readOnly and idempotent annotations, the description discloses detailed matching behavior: normalized substrings for series names, prefix matching for makers, substring matching for chassis codes, and that slash-joined codes are treated as a single string. It also specifies the return shape and empty-results meaning, which is especially valuable given there is no output schema.

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 compact but information-dense, with the primary purpose front-loaded. Every sentence adds useful content—matching rules, return format, and empty-hit behavior—with no filler or redundancy.

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?

For a single-parameter search tool with no output schema, the description provides everything needed: query semantics, matching rules, response shape, and how results should be consumed by other skills. It is complete without being bloated.

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, but the description adds meaning beyond the schema by explaining exactly how each query type matches: series via normalized substring, maker via prefix, chassis via raw substring. This materially helps an agent construct effective queries.

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 opens with a specific verb and resource: 'Find series by name, maker name, or a generation's chassis code.' It then details matching behavior, making the tool's role clear and distinguishing it from the sibling get_* tools, which are retrieval-oriented rather than search-oriented.

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 clearly indicates this tool is the discovery entry point, saying to 'pass the ids in the hits to the other skills.' It also explains empty-hit semantics. It does not explicitly state when not to use it versus a specific sibling, but the 'other skills' routing provides practical usage context.

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