Open slots

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

Annotations already declare readOnly, idempotent, non-destructive and openWorld, so the safety profile is covered. The description adds real value beyond them by disclosing the computation basis (shifts, time off, bookings) and that results are derived locally, which explains the existence and effect of the 'fresh' cache-bypass parameter.

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 sentences, no waste, with the core computation and scope front-loaded before the usage cue. Nothing could be removed without losing signal.

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 read-only availability query with no output schema, an agent has enough to call it correctly: date, duration, optional staff filter, and the knowledge that results are locally derived. It stops short of describing the shape of the returned slots, but the derivation sentence largely implies it.

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 all five parameters are already documented with patterns, bounds and defaults. The description only echoes scope ('one date', 'per staff member') and adds no format, interaction or defaulting detail beyond the schema. Baseline 3 applies.

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?

States a specific verb+resource+scope: free time per staff member for a single date, computed from shifts, time off and bookings. This is clearly distinct from listing tools like calendar_agenda or staff_schedule, though no sibling is named explicitly.

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?

"Use it before proposing a time to a client" gives one concrete workflow cue, which implies the tool's role in a booking flow. However, there is no explicit when-not guidance and no alternatives named (e.g., calendar_agenda for existing bookings, staff_schedule for raw shifts).

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