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

The description discloses that the operation persists to the user catalog and that the id is optional, with a slug generated from the part number. Lacking annotations, it partially carries the burden of explaining side effects, but omits permissions, error behavior, or duplicate handling.

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 entire description is one concise sentence with two informative clauses. Every word earns its place, making it efficient and front-loaded with no fluff.

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 nine parameters, no output schema, and no annotations, the one-sentence description is insufficient. It only addresses id and part, leaving the majority of the input structure and expected behavior undefined for the agent.

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 only 11%, with only 'part' documented. The description adds meaning to 'id' (optional, slug generation) but leaves the other seven parameters (cat, src, desc, unit, keywords, footprint, interface) unexplained, failing to compensate for the low 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 'Add parts' with persistence in the user catalog, specifying a verb and resource. It distinguishes from sibling tools like parts_update and parts_remove by the add action, though it doesn't explicitly contrast them.

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?

No guidance is provided on when to use this tool versus alternatives like parts_update or parts_remove. The intended use is only implied by the tool name and the brief phrase 'user catalog'.

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