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

Annotations already mark it as destructive and non-idempotent, but the description adds important behavior: URL expires in 5 minutes, 25 MB max, approval is required, and writes are never retried automatically. These details go meaningfully beyond the annotations.

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 front-loaded with purpose, then gives the sequence and constraints in compact sentences. Every sentence carries operational value with no filler.

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?

There is no output schema, and the description does a good job explaining the returned presigned URL and s3_key plus key constraints. It still omits some required body-field details (notably file_name and content_type), so it is not fully self-contained.

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 33%, and the description compensates partially by explaining confirmed=true and the 25 MB file_size cap. However, it does not explain the required body.file_name, content_type, or path.id semantics, leaving a clear gap for a low-coverage 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?

Names the specific action (get file upload URL) and identifies it as step one of attaching a file. It enumerates the return values (presigned URL and s3_key) and clearly separates this from the sibling registration endpoint POST /files.

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 states the sequence: use this first, PUT bytes to the URL, then register the s3_key with POST /files. It also states the approval precondition and confirmed=true requirement, leaving little inference for the agent.

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