Microsoft 365 MCP Server

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

While annotations establish readOnlyHint=true, the description adds valuable behavioral context: it explains that only a default subset of properties is returned, describes how to access custom properties and extensions (aligning with openWorldHint), and clarifies the OData query pattern. It does not contradict annotations.

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 informationally dense but contains unnecessary verbosity: references to a 'Properties section' (unavailable to the agent), 'do a GET operation' (implementation detail), and Microsoft Graph-specific jargon. The logical flow is sound but could be more front-loaded.

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?

Despite the absence of an output schema, the description adequately characterizes the return value by explaining the default property subset behavior, extension support, and relationship expansion. Given the 6 parameters and OData complexity, this provides sufficient context for successful invocation.

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 100% schema coverage, the baseline is 3. The description adds meaningful semantic context by explaining that '$select' is used for non-default properties (OData pattern) and referencing 'relationships' (mapping to the expand parameter). It could better explain ConsistencyLevel or pagination behavior.

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 identifies the action ('Retrieve') and resource ('properties and relationships of user object'), but it fails to explicitly specify that this targets the *current* or *authenticated* user, relying instead on the tool name to convey this. It distinguishes from siblings like 'get-outlook-contact' by focusing on the user identity itself.

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 useful guidance on when to use the '$select' parameter versus default properties, and identifies the Microsoft Entra ID for customers use case. However, it lacks explicit guidance on when to use this tool versus 'list-accounts' or 'select-account' for account management scenarios.

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