fab_list_parts

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

The readOnlyHint annotation already declares the tool is read-only, and the description is consistent with that. The description adds the context that it lists already-generated parts, but it does not disclose anything else beyond what annotations provide, such as ordering or scope of results.

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 a single, front-loaded sentence with no filler. It clearly states what the tool does in minimal words, earning its place.

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 simple, read-only listing operation with one required parameter and an output schema available, the description is sufficient. The annotations cover safety, and the schema covers parameter semantics, so nothing critical is missing.

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?

The input schema covers 100% of the single parameter, including a helpful description linking project_id to fab_create_project. The tool description itself does not add any additional meaning to the parameter, so a baseline score 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 uses a specific verb 'List' and a clear resource 'parts already generated in a project,' making the tool's purpose immediately obvious. It is distinct from sibling tools like fab_create_project and fab_export_stl, which cover creation and export rather than listing.

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 phrase 'already generated in a project' implies the tool is meant to be used after parts have been generated, and the parameter description references fab_create_project as the source of the ID. However, no explicit when-to-use or when-not-to-use guidance is given, nor are alternatives mentioned.

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