Microsoft 365 Core MCP Server

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

Annotations indicate readOnlyHint=false (mutation), idempotentHint=true (safe to retry), and destructiveHint=false (non-destructive). The description adds value by specifying 'secure token handling,' which implies security considerations beyond the annotations. However, it doesn't detail behavioral traits like rate limits, error handling, or token storage, leaving gaps in understanding how the tool behaves in practice.

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-structured sentence that efficiently conveys the tool's purpose and security context. It uses precise language ('Manage OAuth 2.0 authorization,' 'user-delegated access,' 'secure token handling') without redundancy, making it front-loaded and easy to parse. Every word earns its place.

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 tool with 5 parameters, no output schema, and annotations covering basic safety (idempotent, non-destructive), the description is adequate but incomplete. It explains the high-level purpose but lacks details on usage scenarios, error handling, or return values (e.g., what tokens are returned). Given the complexity of OAuth operations, more context would help the agent use it effectively.

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 clear descriptions for all 5 parameters (e.g., 'action' with enum values, 'scopes' with examples). The description doesn't add any parameter-specific semantics beyond what the schema provides, such as explaining scope dependencies or state usage. Given the high schema coverage, the baseline score of 3 is appropriate.

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: 'Manage OAuth 2.0 authorization for user-delegated access to OneDrive and SharePoint files with secure token handling.' It specifies the action (manage authorization), the resource (OneDrive and SharePoint files), and the security context (secure token handling). However, it doesn't explicitly differentiate from sibling tools like 'call_microsoft_api' or 'manage_azure_ad_apps' which might also involve authentication, so it doesn't reach the highest score.

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 doesn't mention prerequisites (e.g., needing OAuth setup), when to choose specific actions like 'get-auth-url' vs 'refresh-token', or how it relates to sibling tools such as 'call_microsoft_api' that might require tokens. This leaves the agent with minimal context for appropriate tool selection.

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