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

No annotations are provided, so the description carries full burden. It discloses rich behavioral details: base64 normalization, signature recognition, format checking, screening before storage, one-hour retention, and telemetry exclusion. These go far beyond what the schema or sibling names would convey, giving the agent a clear model of how input is processed and retained.

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 dense yet structured: first sentence defines the core function, subsequent sentences clarify boundaries, processing steps, supported formats, size limits, and usage. No sentence is redundant; each adds a distinct piece of operational knowledge, making the length justified.

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?

Given four required parameters, no annotations, and no output schema, the description covers all essential context: what the tool does, what it is not, how data is processed and retained, format support, size constraints, fallback for larger files, and how to consume the return value. This is a complete operational picture for an agent.

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?

Even though schema coverage is 100%, the description adds significant meaning beyond the schema: it explains the accepted base64 variants (RFC 4648, base64url, optional padding, ASCII whitespace, data:* prefix), the 2 MiB decoded maximum, that paths/URLs are not accepted, and that the format enum values are 'declared' and 'must match' the bytes. The purpose const is also reinforced with 'general chat attachments use a separate intake.'

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 opens with a specific verb+resource+outcome: 'Turn local manufacturing file bytes into the temporary HTTPS reference used by specification.design_files.' It also delineates what the tool is not ('not a request, provider call, quote, order, payment, or fabrication action'), sharply distinguishing it from the sibling tools that handle requests, quotes, and specification reviews.

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?

Explicit when-to-use guidance is present: it is a 'bounded intake operation' with a clear exclusion list of non-actions. It also provides an alternative for larger files ('use POST /api/upload with purpose=manufacturing_design_file for files up to 8 MiB') and instructs the caller to 'Pass the returned file_reference object unchanged in specification.design_files on the next call'.

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