freebusy_query

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

With no annotations, the description carries full burden. It discloses important behavioral traits: ignores TRANSPARENT events (doesn't block time), ignores cancelled events, expands recurring events, and (implicitly) returns busy slots rather than event details unless include_event_details is set. This goes beyond the schema and helps the agent understand the tool's filtering logic.

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 concise, front-loaded with the core purpose and examples, and every sentence earns its place. It covers usage, scope, and behavioral nuances in 3 sentences without redundancy.

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 moderate complexity (4 params, no output schema), the description is complete: it explains when to use, the default scope, how public (transparent) and cancelled events are handled, and how recurring events are expanded. The only minor omission is the return format (likely a list of slots), but that is inferable and not critical for calling.

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%, so the schema already documents all parameters. The description adds value by explaining the default behavior of 'calendar_url' (omit to consider every calendar) and 'include_event_details' (off by default because the answer is slots). This enrichment clarifies the purpose of these optional parameters beyond their type descriptions.

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 purpose: finding free/busy time in a date range, with specific example queries. It distinguishes itself from siblings like calendar_query and list_events by focusing on availability. The description's verb 'Find' and resource 'free and busy time' are specific and unambiguous.

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 explicitly mentions when to use this tool (e.g., 'when am I free?', 'am I available Tuesday afternoon?') and provides guidance on alternatives: it searches all calendars unless one is given, implying you might use list_calendars first to get a specific calendar. It also differentiates from list_events by noting it ignores transparent and cancelled events, which is a key distinction.

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