import_email

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

Annotations only provide destructiveHint=false, leaving behavioral disclosure to the description. The description adds meaningful context: messages are inserted via IMAP APPEND, nothing is sent, and raw can corrupt or reject legacy 8-bit content, with rawBase64 as the safe alternative. It does not cover return values or duplicate-handling, but the disclosed behavior is substantial.

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 sentences, each earning its place: purpose, use cases, and encoding caveat with parameter selection. The phrase 'inserts a message directly into the mailbox' is slightly redundant with 'IMAP APPEND', but it serves to emphasize the non-sending nature. The content is well front-loaded and not bloated.

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 covers purpose, use cases, behavioral nuance, and parameter selection; the schema fully documents each parameter. No output schema exists, but the description adequately prepares an agent for an import operation with encoding pitfalls. Minor omissions like return values or behavior when a target folder does not exist are acceptable given the tool's moderate complexity.

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 baseline 3 applies. The description adds real value by explaining the charset pitfall and explicitly recommending rawBase64 for non-UTF-8 content, reinforcing the schema's 'exactly one required' constraint. markAsRead and targetFolder are already fully covered by the schema, so no additional description is needed.

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 opens with a specific verb and resource: 'Import a raw RFC822 message (.eml content) into a folder via IMAP APPEND.' It states the mechanism, destination, and explicitly differentiates from sending ('Does not send anything'), which makes it distinct from send_email/draft siblings.

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?

Concrete use cases are given: 'restore a backed-up message or migrate mail from another provider's export.' It also provides parameter-level guidance, directing users to rawBase64 for non-UTF-8 content. It does not explicitly name sibling alternatives, but the 'Does not send anything' clause implicitly excludes send_email, so context is clear without fully explicit exclusions.

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