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

With no annotations provided, the description carries full responsibility for behavioral disclosure. It covers read-only status, auth requirements, non-destructiveness, and failure semantics ('unknown or malformed entries do not fail the call, each simply returns found:false'). This is exemplary for a tool lacking structured annotations.

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 two sentences, front-loaded with the primary function and constraints, then providing output shape and safety guarantees. Every clause adds value with no filler or repetition.

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 tool with one parameter and no output schema, the description thoroughly covers input limits, per-row output fields, summary counts, error behavior, auth, and safety. It leaves no significant gaps for an agent to invoke the tool correctly.

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 the parameter description already explains maxItems, deduplication, and punctuation tolerance. The tool description adds the context of 'up to 200 part numbers' but does not materially enhance the parameter semantics beyond what the schema provides, so the baseline of 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?

The description opens with a specific verb and resource: 'Check up to 200 part numbers in one call.' It immediately distinguishes itself from the single-part sibling by explicitly directing users to lookup_part for one part. This clearly identifies the tool's scope and unique role.

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?

Explicit usage context is provided: it is for bulk checking, is read-only with no auth, and the description states 'for a single part use lookup_part,' naming the alternative. This gives the agent clear guidance on when to select this tool over its siblings.

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