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

readOnlyHint already declares this as a safe read. The description adds real value beyond that: results are grouped by day, labelled in the family's state time zone, and each time carries the date_time value required by get_booking_link. It stops short of pagination or result-size behavior, but for a read-only lookup this is solid disclosure.

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?

Front-loaded with step number and purpose, then use/don't-use guidance and a concrete example. Every line earns its place with no filler.

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 no output schema, the description carries the burden of return-value explanation and does so well (grouped by day, state time zone, chained date_time). It could say more about unsupported-state behavior or empty results, but the essentials for correct invocation and follow-up are present.

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 baseline is 3; the description adds an example invocation and clarifies the chaining role of provider_id ('from search_providers or recommend_care') and that the time zone defaults to the state's main zone, giving a bit more than the schema alone.

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 and resource ('Returns open appointment times for one clinician and service') and positions itself as 'Step 3 of find_a_clinician', which cleanly separates it from search_providers/recommend_care and from get_booking_link.

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?

Explicit 'Use when' (a clinician is chosen and the family wants open times) and 'Don't use when' (no clinician chosen yet) clauses, with named alternative tools that handle the pre-selection case. An agent knows exactly when to route here.

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