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

No annotations are provided, so the description carries the full burden. It correctly indicates a read-only lookup operation by stating 'Look up' and describing the return. However, it lacks disclosure of potential error handling, partial results, or any authorization requirements. The description is honest but could add more behavioral context.

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 consists of two concise sentences with no wasted words. It front-loads the core action 'Look up a batch of part numbers' and immediately adds the batch limit and output summary. Every sentence is informative.

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 low complexity (one required parameter, no output schema, no annotations), the description covers the essential purpose, input, batch limit, and output nature. It does not address error behavior or response format, but for a straightforward search tool, it is reasonably complete.

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% since the only parameter 'partNumbers' has a description. The tool description adds value beyond the schema by explaining that it processes a batch, sets the maximum size, and describes the output (per-part summary and existence). This goes beyond the baseline of 3 for high coverage.

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 the verb 'Look up a batch of part numbers', the resource 'PartsTable catalog', and the output 'per-part identity summary and whether each exists'. It also specifies the batch size limit of 25, which distinguishes it from sibling 'get-part' (likely single-part lookup).

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 use for batch part number lookup and mentions the size limit, but does not explicitly state when to use this tool vs. siblings like 'get-part' for single parts or 'validate-pn' for validation. No alternatives or exclusions are given.

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