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, indicating this is a destructive mutation that can accept additional properties. The description adds no behavioral context beyond 'update'—it doesn't explain what 'destructive' means (e.g., overwrites existing properties), authentication needs, rate limits, or error conditions. However, it doesn't contradict the 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 a single, efficient sentence with no wasted words. It's front-loaded and gets straight to the point, making it easy to parse quickly.

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 complexity (4 parameters, nested objects, no output schema) and annotations indicating a destructive mutation, the description is inadequate. It doesn't explain the update behavior (e.g., partial vs. full updates), response format, or error handling, leaving significant gaps for an agent to use the tool correctly.

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%, providing good documentation for most parameters. The description adds no parameter-specific information beyond the generic 'properties of a contact object,' failing to clarify which properties are updatable or how to structure the update. With high schema coverage, the baseline is 3, and the description doesn't enhance understanding.

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 'Update the properties of a contact object' clearly states the verb ('update') and resource ('contact object'), making the purpose immediately understandable. It doesn't explicitly differentiate from sibling tools like 'update-calendar-event' or 'update-todo-task', but the resource specificity is sufficient for clarity.

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 (e.g., needing an existing contact ID), when not to use it, or how it differs from similar update tools for other resources like calendar events or tasks.

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