read_email

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

No annotations are provided, so the description must carry the behavioral disclosure burden. It fails to mention whether reading marks the email as read, requires permissions, or works offline. The description only states the input condition, not the tool's behavior.

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 a single sentence, which is concise, but it is truncated (ends with 'message ID fr...'). As presented, it is incomplete, reducing its effectiveness. A full sentence would score higher.

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 tool has no output schema and no annotations, the description is the sole source of context. It fails to explain the required input (message ID) properly due to schema mismatch, and does not describe the return value or side effects. The tool is simple but the description is insufficiently complete.

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 description implies a 'message ID' parameter is required, but the input schema is empty (no parameters). This is a serious inconsistency: the description suggests an input that the schema does not define, which would confuse an AI agent. With 0 parameters and 100% schema coverage, the description should not add parameter semantics, but it misleadingly does.

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 tool reads the full content of an email from Apple Mail, distinguishing it from list_emails (which lists headers) and search_emails. The verb 'read' combined with 'full content' makes the purpose specific.

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 begins with 'Use this when the user wants the full content of an email', which provides a clear when-to-use. However, it does not mention when not to use it or contrast with alternatives like list_emails or search_emails.

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