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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description still adds real value beyond that: a hard 1 MB size cap, the payload encoding split (raw text vs base64 for binaries), the required files:read scope, and that access is audited. It doesn't say what happens when a file exceeds 1 MB or whether the result is inline content or a link.

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 short sentences, each carrying distinct information: what it retrieves, the size limit, the encoding behavior, the permission requirement, and the audit trail. Front-loaded with the core action and 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?

With an output schema present and full param coverage, the description only needs to cover operational caveats, which it largely does (size cap, encoding, permission, auditing). The remaining gap is failure behavior at the size boundary, a realistic concern for a download tool.

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 100%, with both 'project' (slug or id) and 'file' (id or exact name) documented, so the baseline is 3. The description adds no further meaning about these parameters — notably it doesn't clarify whether 'file' matches by name or id in ambiguous cases.

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 names a specific verb and resource ('Download a secure (encrypted) file') and adds the salient scope constraint ('up to 1 MB'). It does not distinguish itself from the sibling list_files, so an agent must infer that this retrieves a single file's contents while list_files enumerates them.

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?

Usage is implied rather than stated: the agent learns it needs files:read and that files are capped at 1 MB, which hints at when this tool is applicable. There is no explicit when-to-use/when-not guidance and no named alternative (e.g., list_files for discovery), leaving routing to inference.

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