feature_thread_options

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

No annotations exist, so the description carries the full burden and does: it declares read-only, discloses the error contract (INVALID_PARAMS with details.available), and states the mutual-exclusion constraint that diameter cannot be combined with size or designation. That is exactly the operational context an agent needs before calling.

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 purpose, then levels, errors, and examples - a good ordering. It is dense and uses compressed notation ("+ size -> {'designations'}") that is efficient but slightly terse; the three examples rescue it.

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?

No output schema exists, and the description sketches the return keys for each level along with the recommendation shape, so an agent knows what comes back. It doesn't say what a "class" string looks like or whether results are paginated, but for a static enumeration lookup that is minor.

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%, but the description adds semantics the schema cannot express: each parameter combination maps to a different return shape, size/designation/diameter without thread_type default to "ISO Metric profile", diameter is interpreted in `units`, and internal selects hole-bore vs shaft behavior. This is meaning well beyond the per-field descriptions.

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 verb and resource: look up Fusion's thread data, read-only, that feature_thread and feature_hole(thread=...) accept. The sibling tools are named explicitly, so an agent can tell this is a reference-lookup helper, not a feature-creation call.

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 names the two consumers (feature_thread, feature_hole) and lays out the progressive level structure (no args -> thread_types, thread_type -> sizes, etc.), which tells an agent how to drill down. It doesn't state when another tool would be preferred, but for a lookup helper the workflow guidance is clear.

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