Apple Mail MCP Server

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

No annotations are provided, so the description carries full responsibility for behavioral disclosure. While it mentions the return value (confirmation message), it fails to disclose critical file-system behaviors: whether it overwrites existing files at `save_path`, what happens if the attachment is not found, or if multiple emails match the `subject_keyword`.

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?

The description is well-structured with a clear one-sentence summary followed by Args and Returns sections. It is appropriately sized without redundant text, though the Args/Returns headers consume space that could be considered slightly formal for a tool description.

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?

The description adequately covers the parameter semantics given poor schema coverage, and acknowledges the return value. However, for a destructive operation (writing to disk), it lacks necessary safety context regarding file overwriting and error conditions, leaving the agent under-informed about failure modes.

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?

With 0% schema description coverage, the description effectively compensates by documenting all four parameters in the Args section. It adds crucial semantic meaning (e.g., explaining that `account` refers to configured account names like 'Gmail' or 'Work') that the schema titles alone do not provide.

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 (save), resource (attachment), and destination (disk). However, it does not explicitly differentiate from sibling tools like `export_emails` (which might export whole emails) or `list_email_attachments` (which lists without saving), though 'to disk' implies persistence.

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 provides no guidance on when to use this tool versus alternatives like `list_email_attachments` (to verify attachment names first) or `export_emails`. It omits prerequisites such as needing to know the exact attachment name or account beforehand.

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