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

Annotations already declare readOnlyHint and destructiveHint, covering safety. The description adds valuable behavioral context: times are real/live, must not be invented or rounded, and original values must be passed unchanged to create_booking. This goes beyond the structured annotations and informs safe handling of results.

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?

Three sentences, front-loaded with the core purpose, then important usage and data-handling caveats. No wasted words; every sentence earns its place.

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 simple read-only tool with one parameter, the description is complete: it explains the purpose, usage flow, and data-handling constraints. It does not detail the exact response structure beyond 'start/end pairs', but that is sufficient for an agent to use the results appropriately.

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 parameter description already clarifies that event_type is an event slug from list_event_types, not a schedule_id. The tool description adds no additional parameter detail, so it meets the baseline for high coverage but does not exceed it.

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 states a specific verb ('Return') and resource ('live available start/end pairs for one event type'). It clearly distinguishes from siblings: it's about availability for a single event type, not booking or listing event types. The purpose is unambiguous and unique among the sibling tools.

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 gives explicit usage context: 'show them to the person and let them choose' and instructs to pass original values to create_booking. It implies this tool is a prerequisite for booking, but does not explicitly compare to alternatives or state when not to use it. Still, the context is clear and actionable.

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