Microsoft 365 MCP Server

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

Annotations already indicate this is a destructive, non-read-only operation (destructiveHint: true, readOnlyHint: false). The description doesn't add significant behavioral context beyond what annotations provide, though it does mention the critical tip about email addresses which adds some operational guidance. No contradiction with annotations exists.

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 appropriately sized with two sentences - one stating the purpose, one providing a critical tip. Both sentences earn their place, and the structure is front-loaded with the core functionality. The emoji and 'CRITICAL' formatting could be seen as slightly distracting but doesn't significantly impact conciseness.

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 complex mutation tool with 4 parameters, nested objects, no output schema, and annotations that only cover basic safety profile, the description is somewhat incomplete. It doesn't explain what happens after creation, error conditions, authentication requirements, or provide examples. The critical tip about email addresses is helpful but doesn't fully compensate for the complexity of the tool.

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?

With 75% schema description coverage, the input schema already documents most parameters well. The description doesn't add meaningful parameter semantics beyond what's in the schema - it doesn't explain what 'body' should contain, how to specify calendar types, or clarify parameter usage. The baseline of 3 is appropriate given the schema does substantial documentation work.

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's purpose: 'create a new event in a calendar' with specific resource types (user calendar or Microsoft 365 group default calendar). It uses a specific verb ('create') and identifies the resource ('event in a calendar'), but doesn't explicitly distinguish from sibling tools like 'create-calendar-event' or 'update-specific-calendar-event'.

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 clear context about when to use this tool (creating events in user or group calendars) and includes a critical tip about not guessing email addresses and using 'list-users' instead. However, it doesn't explicitly state when NOT to use this tool or name specific alternatives among the many sibling tools available.

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