get-mail-message

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds context about the returned fields (subject, sender, recipients, etc.), but does not disclose any side effects, error conditions, or limitations beyond what the parameter descriptions already provide. It adds modest value beyond the 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 a single, well-formed sentence that front-loads the core action and purpose, then adds the necessary usage hint. No wasted words, and it is appropriately sized for a straightforward tool.

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 get-by-ID tool with a fully described schema and annotations covering safety, the description is complete enough. It tells the agent what the tool does, what it returns, and how to obtain the required ID. There is no output schema, but the description mentions key returned fields. Minor omissions like pagination behavior are already addressed in the fetchAllPages parameter description.

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 has 100% description coverage, with each parameter (expand, select, messageId, fetchAllPages, includeHeaders, excludeResponse) explained. The tool description does not add further parameter semantics beyond restating the message ID in plain terms. The baseline of 3 applies because the schema does the heavy lifting.

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 verb (Get), the resource (single Outlook email message), and key identifiers (message ID). It also lists the content returned (subject, sender, recipients, body, attachment flags) and distinguishes from siblings like list-mail-messages and get-mail-message-mime by emphasizing 'single' and 'full' content.

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 explicitly instructs to use list-mail-messages first to obtain the message ID, giving a clear prerequisite and usage flow. It does not explicitly list alternatives or when-not-to-use, but the contextual guidance is clear and sufficient for typical selection.

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