Microsoft 365 MCP Server

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

Annotations already declare destructiveHint=true and readOnlyHint=false, establishing the safety profile. The description adds no behavioral context regarding deletion permanence (soft vs. hard delete), ETag concurrency requirements, or openWorldHint implications.

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?

While brief (2 words), this represents under-specification rather than efficient conciseness. For a destructive 4-parameter operation, the length is inappropriately short and front-loads no critical information.

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?

Inadequate for tool complexity. A destructive message deletion tool with conditional headers (If-Match) and response body options requires explanation of deletion semantics, idempotency, and return values—none of which are provided.

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 100%, establishing a baseline of 3. The description mentions no parameters and adds no semantic value regarding the If-Match precondition or response options (includeHeaders/excludeResponse).

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 provides a verb ('Delete') and resource ('eventMessage'), but 'eventMessage' conflicts with the tool name 'delete-mail-message' and introduces ambiguity without clarifying scope. It fails to distinguish from siblings like 'delete-mail-attachment' or 'delete-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?

No guidance provided on when to use this versus alternatives, prerequisites (e.g., permissions), or expected outcomes. The destructive nature is only indicated by annotations, not the description text.

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