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

Annotations already establish read-only, idempotent, and non-destructive behavior, so the description only needs to add contextual behavior. It adds valuable details about local time alongside UTC, nationwide availability, and pricing tiers. This goes beyond the schema without contradicting the 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?

Three short sentences with no filler. The core purpose is front-loaded, followed by when-to-use and one key parameter instruction, making the description easy to scan and act on.

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 lookup, the description covers the trigger, scope, pricing, and timezone handling. The absence of an output schema means a bit more detail about the returned slot format could help, but the phrase 'open times' is sufficient for an agent to invoke correctly.

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 description coverage is 100%, so the baseline is 3 even though the description itself only highlights the timezone and pricing parameters. The description adds useful pricing context for duration_minutes but does not explain from_date, days, or limit beyond what the schema already states.

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 uses a specific verb ('List open times') and identifies the exact resource ('Physician Health Review with Anomaly Health'), with pricing context that helps distinguish it from booking or other care tools. It clearly communicates what the tool does and its scope ('Available in all US states').

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 gives an explicit trigger condition: 'Use after the user decides to talk to a real doctor.' It also tells the agent to pass the timezone, which is actionable guidance. It does not explicitly name sibling tools as alternatives, but the use-after condition is clear enough to route selection.

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