catalog_check

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

With no annotations, the description carries the full burden and does so well: it declares the tool is offline and deterministic, enumerates every return `code` with its meaning, specifies that `ok` is True only for `stocked`, and explicitly warns that `not_catalogued` is an absence of evidence rather than a claim of unavailability. That is exactly the kind of non-obvious behavioral context an agent needs.

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?

Front-loaded with the core question, then the input modes, then the return contract. The code enumeration is long but each entry is load-bearing since no output schema exists; only slight verbosity in the branching explanations.

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?

There is no output schema, so the description must describe the return shape — and it enumerates the full result object and the meaning of each status code, including edge cases like cut-to-length stock and undesignated inputs. Complete for the task.

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 0% with two undocumented parameters, so the description must compensate; it does by defining `designation` as a canonical designation, giving concrete format examples ('ISO 4762 M4×12 A2', '608-2RS'), and explaining that `handle` refers to a part whose designation was stamped at generation. It doesn't clarify precedence if both are supplied, minor gap.

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 decision question ('Is this exact part something you can buy off the shelf?') with a clear resource (catalog stock lookup), and its scope is distinct from siblings like catalog_search, catalog_nearest, and designation_check. An agent can tell immediately what question this tool answers.

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?

Explains the two accepted input forms and cross-references catalog_search's `not_covered` field for the out-of-corpus case, which gives useful context. However, it never states when to prefer this over designation_check or catalog_search/catalog_nearest, so sibling routing is only partially addressed.

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