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

The annotations are all false and carry little behavioral information, so the description bears the responsibility for disclosure. It adds meaningful traits beyond the schema: the resulting link expires in one hour, and entry names are always relative, preventing writes outside the unpack destination. This is useful, non-obvious behavior not available in 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?

Two concise sentences with no filler. The primary action and outcome are front-loaded in the first sentence; the second sentence adds an important security-relevant behavior. Every clause earns its place.

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 tool with 8 parameters, one required parameter, and no output schema, the description adequately covers the core behavior, the returned artifact (download link with one-hour validity), and a key constraint. The remaining parameter details are covered by the exhaustive schema descriptions, so nothing critical is missing 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 description coverage is 100%, so this dimension is at baseline 3. The description adds no parameter-specific detail, but the input schema already provides rich explanations for every parameter, including refusal behavior for dir and password and the default for overwrite. The description does not need to compensate for any coverage gap.

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: 'pack files uploaded with zip_upload into a new .zip' and states the outcome ('get a download link valid for one hour'). It clearly distinguishes this from siblings like zip_upload (uploading) and zip_add (likely adding to an existing archive) by emphasizing that a new archive is created.

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 description opens with 'Call this tool to...' and clearly states the intended use case: packing previously uploaded files into a zip for download. It does not explicitly mention when not to use it or name alternative tools, but the purpose is specific enough that an agent can decide to invoke it.

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