m365_mail_send

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

Annotations already declare readOnlyHint=false, openWorldHint=true, idempotentHint=false, and destructiveHint=false. The description simply restates the action without adding context such as authentication requirements or side effects, but it does not contradict the annotations. The bar is lower due to annotations, and the description adds minimal value.

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 sentence of five words, extremely concise and free of fluff. It states the core purpose without wasted words, though it is so minimal that it could be perceived as under-specified. Still, it earns its place by being efficient.

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 tool is straightforward with full schema coverage and annotations. However, there is no output schema, so the description could benefit from noting that a success/failure response is returned. It also does not mention any prerequisites or post-conditions. For a simple send operation, this is minimally acceptable but not rich.

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 provides detailed descriptions for all 6 parameters, achieving 100% coverage. The description adds no parameter-specific information, so it relies entirely on the schema. Per the rubric, a score of 3 is appropriate when schema coverage is high.

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 'Send an email from your account' clearly states the action (send) and resource (email). However, it does not explicitly distinguish from sibling tools like m365_mail_reply, which also involves sending an email, so it loses a point for lack of sibling differentiation.

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 no guidance on when to use this tool versus alternatives. It does not mention prerequisites, exclusions, or reference any sibling tools, leaving the agent without context for tool selection.

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