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

Annotations cover the safety profile (non-readOnly, non-destructive, non-idempotent), and the description adds genuinely useful behavior beyond them: a file_id return value, a 24-hour expiry for unused files, and explicit size ceilings (6 MB base64 / 100 MB via the POST endpoint). It does not describe error behavior or expiration cleanup semantics, so it is strong but not exhaustive.

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 action and formats, and each clause carries information (formats, sizes, return value, expiry, consent constraint). It is slightly dense with nested parentheses, which mildly impairs readability but not comprehension.

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 an upload mutation with no output schema, the description covers formats, size constraints, the return value (file_id), and downstream usage plus a 24-hour expiry. Missing only edge-case behavior such as failure modes or what happens to expired files already referenced in an RFQ.

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?

With 75% schema coverage, most parameters (name, token, rfq_id) are already documented. The description compensates for the undocumented content_base64 by specifying accepted file formats and size limits, adding real meaning beyond the schema.

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 (Upload) and resource (design file) and enumerates supported formats (STEP/STP, IGES/IGS, STL, 3MF, OBJ, DXF, DWG, PDF, ZIP). An agent can immediately distinguish this from siblings like create_rfq or check_design without opening a schema.

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?

Gives strong workflow context: the returned file_id is 'to pass in create_rfq file_ids', and it points to an alternative upload path (POST /api/v1/rfq/files) for files over 6 MB. It adds a precondition ('Only upload files the user agreed to share'), but does not explicitly name sibling tools or state when not to use this tool.

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