read_message

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

With no annotations provided, the description usefully discloses that reading does not mark the message as read, which is an important side-effect clarification. However, it does not cover other behavioral details such as what happens when the UID is missing, whether permissions are required, or how attachments are represented.

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, front-loaded sentence with no wasted wording. It conveys the operation, inputs, return content, and a key non-mutating behavior efficiently.

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 simple two-parameter read tool with no output schema, the description adequately explains what is returned and that the read is non-mutating. It still leaves clear gaps around usage relative to sibling tools and parameter details such as the folder default.

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 maps both parameters to their purpose: folder and UID locate the message. With 0% schema description coverage, it adds some meaning, but it does not explain the folder default (INBOX) or the UID format and scope.

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 states a specific verb and resource: reading a message's text content and attachment metadata by folder and UID. It is clearly a single-message read rather than a list or search, though it does not explicitly name the sibling tools it differs from.

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: read a message when you already know its folder and UID. The description gives no explicit guidance on when to use this instead of search_messages or list_messages, nor any exclusions or prerequisites.

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