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

Annotations already cover readOnly, idempotent, non-destructive, and open-world behavior, so the bar is lower; the description nonetheless adds real value by disclosing the response shape (title + link) and the negative-result behavior. The 'that library only' scope note sits slightly in tension with openWorldHint=true, but it describes corpus scope rather than world-openness, so this is a clarification rather than a contradiction.

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?

Two sentences with no filler. The resource scope and return shape come first, and the miss-handling caveat follows naturally.

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 two-parameter read-only lookup with no output schema, the description supplies what an agent needs: what corpus is searched, what comes back (title and link), and what happens on a miss. Nothing material is missing.

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% and both parameters already carry examples (Bobcat, T590), so the schema does the heavy lifting. The description's phrase 'for a make and model' maps to the params but adds nothing about the fact that make is required while model is optional, leaving that entirely to 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?

States a specific verb (finds), a precisely scoped resource (operator/service/parts manual or spec sheet for a make and model in the Discount Equipment library), and the return payload (title and link). No sibling tool does manual lookup, so the tool is easily distinguished from decode_vin, recall_lookup, and the cost/health calculators.

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?

Clearly frames the context of use: this searches the Discount Equipment library only, and the caller should expect an explicit 'nothing found' answer when the machine is absent. It does not name alternatives or prerequisites, but no sibling tool overlaps functionally, so the routing gap is small.

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