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, establishing the read-only safety profile. The description adds valuable behavioral context that the operation excludes hidden folders by default and documents the navigation pattern for folder hierarchies, though it omits pagination or rate limit details.

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?

Four well-structured sentences with zero waste: purpose statement first, navigation hint second, and hidden folder behavior last. Every sentence delivers distinct value without redundancy. Appropriate length for the tool's complexity.

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 rich input schema (13 parameters with 100% coverage) and readOnly annotations, the description covers the essential behavioral quirks (hidden folders, hierarchy navigation). No output schema exists, but the description adequately addresses the non-obvious aspects of the operation.

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 schema handles basic parameter documentation. The description adds crucial semantic meaning beyond the schema for 'includeHiddenFolders' by explaining the default exclusion behavior (schema only states 'Include Hidden Folders'), compensating for the mechanical schema descriptions.

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?

Description clearly defines the tool's purpose with specific verb ('Get') and resource ('folder collection under the specified folder'). It effectively distinguishes from sibling 'list-mail-folders' by explaining the '/me/mailFolders' shortcut for top-level folders, implying this tool is for nested/child folders.

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?

Provides clear context for when to use this tool versus top-level folder listing by referencing the shortcut path. Explains default behavior regarding hidden folders and how to override it. Could be more explicit by explicitly naming the sibling tool for top-level folders, but the guidance is clear.

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