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

Annotations only cover readOnlyHint and openWorldHint; the description adds real behavioral context beyond them — it is a house tool ('Dirtsmith-built'), costs nothing ('Free'), and returns results ordered cheapest-first exposing a use_url field. That ordering and cost disclosure is exactly the value-add the annotations do not provide.

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?

A single compact sentence with no filler, front-loading provenance, action, and return shape in order of relevance. Every clause earns its place.

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 an output schema present the description need not explain return values, and it goes further by disclosing the cheapest-first ordering and use_url field. It is complete enough to call correctly; only the sibling-routing context is thin.

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% and there is only one parameter, so the schema already documents q fully (with its own example). The description restates 'by keyword' without adding format, syntax, or multi-keyword guidance, so baseline 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?

States a specific verb ('search') and resource ('this rate sheet' of outside tools) plus the return shape (matching tools cheapest-first with use_url). It is clear what the tool does, but it does not differentiate itself from near-siblings like similar_tools, match_tool, or list_tools, so an agent still has to infer which search-family tool to pick.

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 gives no when-to-use guidance, no exclusions, and names none of the many search/lookup siblings. 'Free' hints at cost preference but never states that this is the keyword-search entry point versus list_tools or match_tool, leaving usage to inference at best.

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