icloud-mcp

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

With no annotations provided, the description carries the full burden and effectively discloses the return structure (filename, MIME type, size, IMAP part ID) and the non-destructive, read-only nature of the operation. It could improve by mentioning behavior when no attachments exist.

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 efficiently structured sentences with zero waste: first establishes the action and key behavioral constraint (no download), second specifies return fields. Information is front-loaded and dense.

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?

Given the absence of an output schema, the description appropriately enumerates the returned fields for each attachment. For a 2-parameter tool with complete schema coverage, this is sufficient, though explicitly stating it returns an array would be ideal.

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 input schema has 100% description coverage ('Email UID', 'Mailbox name'), meeting the baseline. The description adds context by stating these parameters identify 'an email' but does not elaborate on UID format or mailbox naming conventions beyond the schema.

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 specific action (List) and resource (attachments), and distinguishes from sibling tool 'get_attachment' by emphasizing 'without downloading them', clarifying this is a metadata-only operation.

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 phrase 'without downloading them' implicitly guides the agent to use this for metadata inspection versus 'get_attachment' for content retrieval. However, it lacks explicit 'when not to use' guidance or prerequisites (e.g., requiring the email UID to exist).

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