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

Annotations already declare read-only, open-world, idempotent, and non-destructive behavior, so the description does not need to restate safety. It adds value by listing the returned fields, which is useful since no output schema exists, but adds no caveats about errors, permissions, or rate limits.

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 concise sentences, zero filler. The core action is front-loaded, followed by the return payload list and a direct usage cue.

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 single-parameter read-only tool with full schema coverage and rich annotations, the description provides all necessary calling context. The absence of an output schema is compensated by the explicit enumeration of returned fields.

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 coverage is 100%, and the id parameter is already described as 'The Microsoft Graph event ID to retrieve.' The description echoes the role of the parameter ('by its ID') but adds no deeper semantic detail beyond what the schema 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?

States a specific verb and resource: 'Get full details of a single Outlook / Microsoft 365 calendar event by its ID.' It clearly differentiates from list_events by targeting a single event and enumerating the returned fields.

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?

Explicitly says 'Use after list_events to inspect a specific meeting,' providing clear context and a sequencing cue. It does not mention exclusions or alternative tools, but for a simple lookup tool this is sufficient.

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