Microsoft 365 MCP Server

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

Annotations already declare readOnlyHint=true and destructiveHint=false, confirming the safe read-only nature. The description adds no behavioral context beyond 'Retrieve', failing to explain pagination behavior (top/skip/fetchAllPages), OData query patterns (filter/select/expand), or that it returns metadata rather than binary content.

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?

Extremely concise at six words, but inadequately sized for the tool's complexity. While no words are wasted, the single sentence fails to earn its place by providing sufficient value for a 12-parameter tool with OData-style querying capabilities.

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?

Severely incomplete given the complexity: 12 parameters including pagination, projection (select/expand), search/filter, and response control (excludeResponse). With no output schema and minimal description, agents lack context for the attachment object structure and query capabilities.

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%, with all 12 parameters documented in the schema (top, skip, filter, messageId, etc.). The description mentions no parameters, but the baseline score of 3 applies since the schema carries the full burden.

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 uses a specific verb ('Retrieve') and resource ('attachment objects'), but fails to specify these are email attachments (omitting 'mail' from the name) and lacks scope clarification regarding the required messageId parameter. It does not distinguish from sibling get-mail-attachment.

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 get-mail-attachment (which retrieves content) versus add-mail-attachment. The critical dependency on messageId (required parameter) is not mentioned in the description.

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