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

Beyond the readOnlyHint and openWorldHint annotations, the description adds valuable behavior: times are UTC ISO timestamps that must be converted, the timezone affects which month is read and the booking/invitation, durationMinutes coupling is required, and availability can change between reads. This gives the agent important operational knowledge not present in 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 compact, front-loaded with the core purpose, and each sentence earns its place by covering a distinct operational concern: format, timezone behavior, booking constraints, and freshness.

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?

The tool is simple with an output schema and helpful annotations. The description covers all critical usage details an agent needs: timezone handling, timestamp conversion, durationMinutes pairing, booking-tool linkage, and data freshness. Nothing essential is missing.

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?

The input schema already covers both parameters with descriptions at 100% coverage, so the baseline is 3. The description adds meaning by explaining the timezone's role in month selection and its relationship to book_demo, going beyond what the schema alone communicates.

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 and resource: it gets open times on the Tabflows demo calendar, grouped by meeting length. This clearly distinguishes it from sibling tools like get_demo_booking_link, whose purpose is centered on a booking link rather than availability.

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 clear operational context: pass the person's IANA timezone, use the same timezone for book_demo, and only book a start time under the durationMinutes it is listed with. It does not explicitly name alternatives or exclusion cases, but for this tool the usage 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.