icloud-mcp

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

No annotations provided, so description carries full burden. It discloses the parsing behavior (splitting into email/URL components) which explains output structure, but fails to declare safety properties (read-only), error behavior when header is missing, or whether the operation is idempotent.

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 sentences totaling 17 words. First sentence front-loads the core function; second provides use-case context. No redundancy or filler. Every word 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 2-parameter tool with no output schema, the description partially compensates by describing the return structure ('parsed into email and URL components'). However, it omits behavior when the header is absent. Reasonably complete for low-complexity tool but could specify return format more explicitly.

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% with 'uid' and 'mailbox' already well-described in the input schema. Description adds no additional parameter semantics (e.g., UID format, mailbox path conventions), so baseline 3 is appropriate per scoring rules for high-coverage schemas.

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?

Description provides specific verb ('Get'), exact resource ('List-Unsubscribe header'), and processing detail ('parsed into email and URL components'). Clearly distinguishes from sibling 'get_email' by specifying header-specific extraction rather than full message retrieval.

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?

Provides implied usage context ('Useful for AI-assisted inbox cleanup') suggesting when to use it, but lacks explicit when-not guidance or comparison to alternatives like using 'get_email' and parsing manually. No mention of prerequisites like email UID availability.

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