Download a photo or file

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

With no annotations, the description carries the full burden and does so well. It discloses the inline return for images, the short-lived download URL plus metadata for other files, and the required 'files:read' scope. This goes beyond a basic action statement.

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 sentences, each earning its place: what it fetches, how results are returned, and what permission is needed. The most important information is front-loaded.

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 a two-parameter tool with no output schema and no annotations, the description covers the essential invocation details, return behavior, and auth requirement. The only minor gap is the vague 'plus metadata' and no mention of failure modes, but these are not critical for correct invocation.

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 100%, so the baseline is 3. The description's phrase 'the id of what holds it and the id of the file' loosely maps to scope_id and file_id but adds no new detail beyond the already detailed schema descriptions with concrete id prefixes.

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 ('Fetches') and a clear resource ('photo, voice recording or file'), and identifies the exact id pair needed. It also distinguishes the tool from the sibling list by focusing on media/file download rather than task or submission management.

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?

The context of use is implied: call it when you hold a scope_id and file_id and need the actual photo/recording/file. However, there is no explicit guidance about when not to use it or which alternative to choose, despite a list of sibling tools.

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