import_email

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

Annotations only state destructiveHint=false, which the description respects. The description adds useful context: the message is inserted directly via IMAP APPEND and does not send anything, clarifying the side effects. However, it could disclose more about behavior such as handling of duplicate messages or return values, but the provided context is already valuable.

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 two sentences, front-loaded with the primary action, followed by use cases and a clarifying exclusion. Every sentence earns its place, with no fluff or repetition of schema details.

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 tool with moderate complexity and no output schema, the description covers the main function, use cases, and non-sending behavior. It lacks mention of return values or error scenarios, but these are not critical given the simplicity and good schema coverage. Overall, it is sufficient for an agent to invoke correctly.

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 description coverage is 100%, so the schema documentation for parameters is sufficient. The description does not add extra meaning beyond the schema, but that is acceptable given the baseline. It mentions 'folder' which relates to targetFolder, but no new semantic details are provided.

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 action: 'Import a raw RFC822 message (.eml content) into a folder via IMAP APPEND.' This is a specific verb and resource, and it distinguishes the tool from siblings by explicitly noting 'Does not send anything,' which differentiates it from send_email and other messaging tools.

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 explicit use cases: 'Use to restore a backed-up message or migrate mail from another provider's export.' It also excludes sending behavior, guiding the agent away from using this tool for sending emails. This effectively communicates when to use vs. alternatives.

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