download_file

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

Goes well beyond the annotations by disclosing the no-overwrite policy, the local-only destination (no external URLs), the SHA-256 verification behavior, and the returned fields (path, bytes, SHA-256). It also adds an untrusted-content warning that no annotation covers.

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?

Three dense sentences with the action, constraints, return contract, and safety note front-loaded; nothing is repeated from the schema and no sentence is 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?

Compensates for the missing output schema by naming return values and adds key constraints, but with 4 params at 25% schema coverage it leaves name/save_as/max_bytes unexplained, which matters for calling it correctly.

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 description coverage is only 25% (uid only), so the description carries most of the load, yet it explains no parameter semantics directly. 'name' (the file selector), 'save_as', and 'max_bytes' are never mentioned, leaving half the contract undocumented in both schema and description.

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 (download) and resource (one listed run file/media) with clear scope limits. The 'run file' framing implicitly separates it from download_artifact_file, but no sibling is named explicitly, so the differentiation relies on the agent reading sibling names.

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?

'One listed run file/media' implies a list_files prerequisite and 'configured local output directory' fixes where output goes. However, no explicit when-to-use vs download_artifact_file or download_history is given, so routing to the correct download sibling is left to inference.

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