Microsoft 365 MCP Server

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

Annotations provide readOnlyHint=false, destructiveHint=true, and openWorldHint=true. The description adds valuable context beyond annotations: it explains the move operation creates a copy in the destination and removes the original, clarifying the destructive nature. However, it doesn't mention rate limits, error conditions, or authentication requirements, which would be helpful given the annotations don't cover these.

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?

Two sentences front-load the core action and its effect. No redundant words or fluff; every phrase contributes to understanding the tool's behavior. Efficiently conveys the move operation and its consequences without unnecessary elaboration.

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 destructive mutation tool with no output schema and 4 parameters, the description is adequate but has gaps. It explains the move behavior well but lacks details on return values, error handling, or dependencies like required authentication. Given annotations cover safety aspects, it's minimally complete but could benefit from more operational context.

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 75%, with two parameters (includeHeaders, excludeResponse) well-described in the schema. The description doesn't add details about parameters like DestinationId format or messageId usage. It implies movement but doesn't explain parameter interactions. Baseline 3 is appropriate since the schema covers most parameter documentation.

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 verb ('Move'), resource ('a message'), and destination ('to another folder within the specified user's mailbox'). It distinguishes from sibling tools like 'delete-mail-message' by specifying relocation rather than deletion, and from 'list-mail-messages' by being a mutation operation.

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 implies usage when moving messages between folders, but doesn't explicitly state when to use this vs alternatives like copying or deleting. No prerequisites (e.g., authentication) are mentioned, though sibling tools include login/logout. It doesn't specify constraints like folder existence or permissions.

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