Standard Parts: Catalogue

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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds real behavioral context beyond that: rows carry a `source` provenance field, coverage is deliberately narrow, and sizes outside a table are refused by name with nearest entries and never interpolated. That is useful, non-redundant disclosure.

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?

Three short sentences, front-loaded with the core purpose before the coverage caveats. Nothing is padded, though the coverage sentence packs several clauses that could be tightened.

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?

An output schema exists, so return values need not be spelled out, and the description covers scope limits and provenance adequately for a filtered lookup tool. It leaves the interplay with std_part_insert implicit, which is a minor gap rather than a blocking one.

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%, so both `query` and `standard` are already documented with examples and the allowed standard list. The description reinforces the coverage limits but adds no syntax or matching semantics beyond what the schema already provides. Baseline 3 applies.

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 states it returns catalogue rows with dimensions and provenance, which is a concrete resource with clear scope. It distinguishes itself from std_part_insert by describing that insert refuses out-of-table sizes, though it does not name the sibling as an alternative in its own right. Slightly abstract framing ('Catalogue rows') keeps it from a 5.

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?

It gives clear coverage boundaries — ISO 261 first-choice M5-M36 (M3-M24 for ISO 4762) and ISO 15 bore numbers 00-10 in the 600x/620x/630x series — so an agent knows when this tool will have results. It also notes what happens for unknown standards. It does not, however, explicitly say when to call this versus std_part_insert (e.g., look up first, then insert).

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