Modify an existing Outlook calendar event by ID to change its subject, start/end time, location, body, or attendees.
Update an existing calendar event
| Name | Required | Description | Default |
|---|---|---|---|
| end | No | New end time | |
| body | No | New body content | |
| start | No | New start time | |
| eventId | Yes | The ID of the event to update | |
| subject | No | New subject | |
| location | No | New location | |
| attendees | No | New list of attendees |
Changes observed during successful MCP inspections.
v2.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description does not disclose behavioral traits such as effect on existing data, error handling, or whether partial updates are supported. The description only restates the function name.
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 sentence with no wasted words. It is concise and front-loaded with the core action, though it could be slightly more informative without sacrificing brevity.
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 of 7 parameters (including nested objects) and no output schema, the description is far too minimal. It does not explain how parameters interact, expected formats, or what the function returns.
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?
The input schema covers 100% of parameters with descriptions, so baseline is 3. The tool description adds no additional semantic context beyond what the schema already provides.
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 action ('Update') and the resource ('existing calendar event'), making the tool's purpose unambiguous. It is specific and distinguishes from sibling tools like 'create_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?
No guidance is provided on when to use this tool versus alternatives (e.g., creating vs. updating events). There is no mention of prerequisites or scenarios where this tool is not appropriate.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.