list_library

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

No annotations, so the description carries the burden; it does disclose the filesystem source, the env var and default path, and that matching is case-insensitive substring. It omits what happens if the library folder is missing/empty, whether the listing is recursive, ordering, or size limits — meaningful gaps for a filesystem-backed tool.

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?

Two tight sentences: capability and scope first, filter and follow-up action second. The env var/default parenthetical earns its space by telling the agent where files actually come from.

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?

Output schema exists so return shape needn't be explained, and the description covers source, filtering, and the natural next call. Only the edge-case behavior (missing folder, recursion, sort order) is absent.

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% and the single param 'query' is undocumented in the schema, but the description compensates by defining it as a case-insensitive substring filter with a default of no filtering. That's the key semantic (substring, not glob/regex) the agent needs.

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?

Specific verb+resource: lists STEP files (.step/.stp) in the local parts library, including where that library lives (FREECAD_MCP_LIBRARY, default ./library). It also names the sibling (insert_library_part) it feeds, so it's distinguishable from import_step and list_objects.

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?

Explicitly frames the optional substring filter and directs the agent to use the returned relative path with insert_library_part, which establishes the lookup-then-insert workflow. It doesn't state when to prefer this over, say, list_documents or import_step, so not a full 5.

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