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

Beyond the annotations (readOnly, idempotent, non-destructive), the description explains the tool returns fileRefs for each file, reports emptiness as a normal state rather than an error, and clarifies that the draft folder is auto-removed. No contradiction with 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 somewhat wordy but every sentence serves a purpose: it explains the return value, the correct call timing, how to handle an empty result, and the lifecycle of the draft folder. It is well-structured and not redundant.

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?

Without an output schema, the description covers expected output (fileRefs), the edge case of no files yet, and the draft folder's automatic removal. This gives an agent all necessary context to call the tool correctly and interpret results.

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 only parameter uploadId is fully described in the schema as 'The uploadId from create_upload_link.' Since schema coverage is 100%, the description adds no additional meaning beyond what is already provided, so baseline 3 applies.

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 clearly states the tool's purpose: to look for files uploaded via an upload link and return fileRefs for each, which distinguishes it from sibling check tools like check_bounces or check_deliverability.

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?

Provides explicit when-to-use guidance: call after create_upload_link, either immediately after self-upload or after the user confirms. It also advises not to poll repeatedly and what to tell the user when no files have arrived yet, plus a warning about not offering deletion of the temporary draft folder.

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