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

Annotations already declare readOnly, idempotent, and non-destructive hints, so the safety profile is covered. The description adds meaningful behavioral context beyond that: UTC-day grouping, a 31-day range cap, and a strong confidentiality boundary that no clinical data or identifiable appointment details are ever returned. There is no contradiction with 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?

Two sentences with no filler. The first sentence front-loads the action, scope, and range constraint; the second sentence adds the critical exclusion of clinical data. Every clause 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?

The tool is a read-only aggregate operation with a complete input schema, a present output schema, and safety covered by annotations. The description provides the remaining important context: the aggregation unit, range cap, tenant scope, and privacy boundary. Nothing needed for correct invocation 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?

Schema coverage is 100%, so the parameter descriptions already document clinicId, startTime, and endTime defaults. The description adds useful semantic context by specifying a maximum 31-day range and UTC-day grouping, which helps an agent reason about valid ranges and timezone handling beyond the schema.

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 counts scheduled records by UTC day for one tenant-owned clinic. It also distinguishes itself from detailed calendar/clinical tools by explicitly saying it returns aggregate administrative counts only, never appointment identifiers, times, patient information, or clinical data.

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 purpose is clear and the 'aggregate administrative counts only' clause implies this is not the tool for record-level or clinical detail. However, it never names sibling alternatives like list_calendar_events or get_clinic_availability, nor does it give an explicit when-to-use versus when-not-to-use condition.

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