m365_calendar_availability

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

The description adds no behavioral context beyond what the annotations already declare (readOnlyHint, idempotentHint, etc.). It does not explain what 'availability' output looks like, whether it returns per-user free/busy slots, or any details about timezone handling or response structure. With annotations present, the bar is lower, but the description fails to add any value.

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, front-loaded sentence with no wasted words. It precisely communicates the tool's purpose without any fluff, making it highly concise and well-structured.

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 absence of an output schema, the description should explain what the caller can expect in the response (e.g., a list of busy times, availability per user). It does not, leaving a significant gap. The simple nature of the tool does not excuse the lack of return-value information, but the annotations and schema provide some context.

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 fully describes all three parameters (users, startDateTime, endDateTime) with 100% coverage, so the baseline is 3. The description does not add any additional parameter semantics 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 tool's function: checking free/busy availability for users. The verb 'check' is specific, and the resource ('availability for users') is distinct from sibling tools like m365_calendar_list or m365_calendar_today, which focus on listing events rather than availability.

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 implies the tool should be used when free/busy information is needed, but it provides no explicit guidance on when to prefer this over other calendar tools or any exclusions. The usage context is implied by the tool name and description but not explicitly stated.

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