Microsoft 365 MCP Server

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

States 'Read-only' which merely duplicates the readOnlyHint annotation. Includes 'Navigation property' (OData jargon) without explaining behavioral implications. Fails to disclose pagination behavior, rate limits, or that it returns a collection versus a single entity, despite complex query parameters like fetchAllPages and expandExtendedProperties.

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?

Severely undersized for a 14-parameter tool with complex query capabilities. Three short fragments waste space on redundant annotation info ('Read-only') and obscure terminology ('Navigation property') that don't help an agent understand how to invoke the tool effectively.

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?

Inadequate for tool complexity. With 14 parameters supporting OData-style queries (filter, expand, select, etc.), the description should explain the query pattern or return structure. No output schema exists, yet description doesn't hint at return format or pagination.

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 baseline applies. Description adds no parameter-specific context (e.g., no explanation of OData-style filtering, timezone handling, or when to use expandExtendedProperties), but schema compensates adequately.

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?

Uses noun phrase 'The events in the calendar' instead of an action verb (e.g., 'List' or 'Retrieve'), failing to clearly state what the tool does. While it identifies the resource, it does not distinguish from sibling tools like list-calendar-events or get-specific-calendar-event.

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 no guidance on when to use this tool versus alternatives (e.g., list-calendar-events vs list-specific-calendar-events). No mention of prerequisites (calendarId requirement) or filtering use cases despite having complex query parameters.

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