mailpit_get_message

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

Annotations already mark it as read-only. The description adds the 'latest' special value but does not disclose error behavior, return format, or any other side effects or limitations.

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 concise sentence that front-loads the action and includes the key special value in parentheses, with no unnecessary words.

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's simplicity (one parameter, no output schema), the description provides the essential purpose and special value. It lacks a mention of what constitutes 'full message content' but is sufficient for basic usage.

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 already covers the parameter with a clear description. The tool description merely repeats 'by ID (or "latest")' without adding new semantics beyond what the schema provides.

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 uses a specific verb ('Get') and resource ('full message content') and distinguishes itself from siblings like 'mailpit_get_latest_for_recipient' by emphasizing lookup by arbitrary ID or the special value 'latest'.

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 implies usage when you have a specific message ID or want the latest message, but it does not explicitly state when to use this tool versus alternatives like 'mailpit_list_messages' or 'mailpit_get_latest_for_recipient'.

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