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, so the agent knows this is a safe read operation. The description adds 'Read-only' which is redundant but not contradictory, and mentions it's for the 'root folder', providing some context. However, it lacks details on rate limits, authentication needs, or response format that would enhance transparency beyond 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 extremely concise with two short phrases, front-loading the core purpose ('The root folder of the drive') and a key behavioral trait ('Read-only'). Every word earns its place without redundancy or fluff.

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?

Given the tool's moderate complexity (6 parameters, 1 required) and rich annotations (readOnlyHint, openWorldHint), the description is minimally adequate. However, with no output schema, it doesn't explain return values like folder structure or error cases, and it lacks usage context, leaving gaps for an agent to infer proper 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?

Schema description coverage is 100%, so the schema fully documents all 6 parameters. The description adds no parameter-specific information beyond what's in the schema, such as explaining how 'select' or 'expand' work in this context. Baseline 3 is appropriate when the schema does the heavy lifting.

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 retrieves 'the root folder of the drive' with a 'Read-only' operation, providing specific verb+resource. However, it doesn't differentiate from sibling tools like 'list-drives' or 'list-folder-files', which could also retrieve drive-related information, so it misses full sibling distinction.

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 like needing a valid driveId, nor does it compare to sibling tools such as 'list-drives' for broader drive listings or 'list-folder-files' for non-root items.

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