free_busy

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the description need not restate safety. The phrase 'visible iCloud events' adds context about data source and permissions, but does not explain what 'busy intervals' means in terms of return format (e.g., date ranges, granularity) or behavior when no events are present.

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 one key piece of information ('visible iCloud events'). It is concise and front-loaded with the verb 'Compute'. However, it could be slightly more informative without adding bulk.

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 required parameters, no output schema) and poor schema coverage (0%), the description is not complete. It does not explain return values (e.g., busy time slots) or parameter semantics. Annotations provide safety context but do not compensate for missing behavioral and parameter details.

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 0%, meaning no parameter descriptions exist in the schema. The description provides no parameter details at all—it does not explain what format 'start' and 'end' expect (e.g., ISO 8601), what timezone values are valid, or how calendar_id is used. The schema only shows types and names, so the description should compensate but fails to do so.

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 uses a specific verb ('Compute') and resource ('busy intervals from visible iCloud events'). It distinguishes itself from siblings like 'list_events' and 'find_conflicts' by focusing on availability rather than event details or conflict detection.

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 provides no guidance on when to use this tool versus alternatives. Given sibling tools like 'list_events' (which lists events) and 'find_conflicts' (which might find overlapping events), it does not clarify that this tool returns busy intervals for availability checks or when the other tools are more appropriate.

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