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

Annotations already declare readOnlyHint=true, so the read-only nature is covered. The description adds context about the FHIR Slot resource and bookingUrl, and clarifies that the server never books. This provides useful behavioral detail beyond annotations, but no further depth on authentication or rate limits.

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 two concise sentences. The first covers purpose and scope, the second adds key behavioral detail. Every sentence provides value with no unnecessary words.

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?

Given the tool's simplicity, the lack of output schema, and annotations covering safety, the description is complete. It explains what is returned (slots with FHIR resource and bookingUrl) and the booking behavior, which is sufficient for correct invocation.

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%, with all four parameters well-described in the input schema. The description adds only the phrase 'up to 14 days ahead', which aligns with the days parameter. It does not significantly enhance parameter understanding 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 clearly states the tool retrieves free appointment slots for one specific service variant at one clinic, within a 14-day window. It uses specific verbs and resources, and distinguishes itself from sibling tools that handle dates, services, or clinics.

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 implies usage when slots for a specific service and clinic are needed, and mentions the booking flow. However, it does not explicitly state when not to use or directly name alternative tools, though the differentiation is clear from the sibling context.

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