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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely new behavioral context: a 7-day and 100-slot cap on results, day-grouping of output, and that no patient or dentist details are returned.

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, each earning its place: trigger, return shape with explicit limits, and exclusion. The most important routing information is front-loaded.

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?

With annotations covering safety and an output schema covering return structure, the description only needs to add scope and limits – which it does. An agent has everything needed to call this correctly and not mistake it for a booking tool.

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?

There is a single parameter (clinicId) and schema description coverage is 100%, with the pattern '^[0-9a-f]{24}$' already documented. The description adds nothing about the parameter, so the baseline of 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?

The description states a concrete verb and resource – returning open online-booking slots grouped by day – and the title reinforces it. It is clearly distinguishable from siblings like get_clinic_schedule_summary or list_calendar_events because it is scoped to bookable availability windows.

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?

It gives a clear triggering condition ('when someone asks when their dental practice has free appointment times or the next available slot') and an explicit exclusion ('Not for booking or holding a slot'). It does not name the sibling tool that handles booking, so the routing is clear but not fully closed.

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