get_freebusy

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

No annotations are provided, so the description carries the transparency burden. It discloses the read-only nature via 'Query' and mentions the required OAuth scope, which is useful. But it does not describe return format, error behavior, or how free/busy results are structured, so it only partially compensates for missing 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 two sentences, front-loaded with the primary purpose. Every word earns its place—purpose, usage hint, and auth requirement are all included without fluff.

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?

This is a moderately simple query tool with no output schema and no annotations. The description covers the 'why' and 'when' but not the 'what returns'—the agent does not know the response structure. For a query tool, this is a moderate gap, but the schema covers inputs well, so the description is minimally adequate.

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 the baseline is 3. The description adds no extra detail beyond the schema; it only summarizes the overall purpose ('one or more users in a time range') which is already evident from required params. It does not clarify formats or semantics beyond the schema.

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: 'Query freebusy windows for one or more users in a time range.' The verb 'Query' plus the specific resource 'freebusy windows' distinguishes it from sibling calendar tools like list_calendar_events or get_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 clear context with 'Use to find a meeting slot,' which tells the agent when to apply this tool. It also mentions the required permission scope. However, it does not explicitly state when not to use it or suggest alternative tools, stopping short of a 5.

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