Find a free slot

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

Annotations already indicate readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds behavioral context beyond the schema by noting that the search respects existing events and working hours, which helps the agent understand what influences the returned slots.

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?

Two short, purposeful sentences. The first states the function and constraints; the second explains why to use the tool over manual calculation. No filler or redundant repetition of schema fields.

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 two-parameter read-only tool, the description provides sufficient context to call it correctly: what it finds, what it respects, and why it should be preferred over manual gap calculation. It does not describe the return format, but the absence of an output schema is partly mitigated by the clear 'open slots' result implied in the description.

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 both parameters are already documented plainly: date expects YYYY-MM-DD and minutes has a default of 30. The description's phrase 'given length' only echoes the minutes parameter without adding new semantic detail, so the schema carries the load.

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 names the action ('find'), the resource ('open slots of a given length on a date'), and the constraints ('respecting existing events and working hours'). It also distinguishes itself from the manual approach of reading the calendar, making its purpose easy to separate from sibling calendar 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 explicitly recommends using this tool instead of reading the calendar and computing gaps manually, which gives clear when-to-use guidance and a rationale. It does not name sibling alternatives directly, but the contrast with 'reading the calendar' is enough to orient an agent among the calendar-related siblings.

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