icloud-mcp

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

With no annotations, the description carries the full burden. It discloses that the tool 'fetches the original email body' (read behavior) and formats it as a forwarded block, plus prepends notes. However, it omits whether the original email is marked as forwarded, if a copy appears in the sent folder, or what the return value indicates.

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 well-structured sentences: purpose statement, mechanism explanation, and feature support. No redundancy or filler. Each sentence adds distinct value (what it does, how it handles content, what formatting it supports).

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?

Adequate for basic invocation given the comprehensive schema, but gaps remain regarding side effects and return values due to the absence of annotations and output schema. Missing: whether the operation creates a sent item, marks the original, or returns the new message ID.

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%, establishing a baseline of 3. The description references 'one or more recipients' (to) and 'plain text and/or HTML note' (note/html), aligning with the schema but adding minimal semantic detail beyond what the schema already provides for the 6 parameters.

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?

Clear verb ('Forward') and resource ('existing email'), with specific detail about including the original body as a forwarded block. Distinguishes implicitly from siblings like compose_email or reply_to_email by describing the forwarding mechanics, though it doesn't explicitly name alternatives.

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?

No guidance on when to use this versus similar tools like reply_to_email or compose_email. Given the sibling list includes both reply_to_email and get_email, explicit differentiation (e.g., 'use this to send to new recipients rather than responding to the original sender') would prevent selection errors.

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