List Mailbox Inbox Messages

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

The description adds valuable context beyond annotations by stating that email content and metadata are untrusted, which is a security consideration. It does not contradict the readOnlyHint or openWorldHint annotations.

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 concise at two sentences, front-loading the action and then providing a useful warning. No superfluous content.

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 the basic purpose and a security warning, but for a paginated list endpoint with 8 parameters, it does not explain pagination behavior (limit, position) or detail the output schema, which exists. Adequate but could be more 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?

Schema description coverage is only 13%, with only the 'id' parameter described. The description mentions filters generically but does not explain parameters like folder_id, folder_role, position, limit, has_keyword, not_keyword in detail, nor their behavior.

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 lists inbound/JMAP messages for a mailbox with various filters. It distinguishes from siblings like shipmail_list_messages by specifying 'inbox messages' and adds a security note about untrusted data.

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?

Usage is implied but not explicitly stated. No direct comparison to alternatives like shipmail_list_messages or shipmail_get_message is given, nor when to prefer this over other list tools.

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