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

Annotations provide openWorldHint=true but readOnlyHint=false; the description adds key behavioral context by stating 'An available result is tentative and is not a hold or reservation' and that it 'Returns only available, unavailable, or unknown.' This clarifies the non-committal nature of the result, going beyond the annotation flags. No contradiction with annotations is present.

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 a compact two-sentence paragraph, front-loaded with the primary purpose and including the booking URL as a call-to-action. Every sentence contributes value: purpose, input consistency, output behavior, and parameter rule. 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?

There is no output schema, so the description explicitly states the return set: 'Returns only available, unavailable, or unknown.' It also clarifies the tentative nature of availability and the hours condition. For a simple check tool with a clear sibling reference, this is adequate; minor gaps like error handling are not critical.

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?

The schema already describes the 'hours' parameter with 'Required for hourly service; omit for airport and one-way rides.' The description repeats this ('Hourly rides require hours (1–24); other ride types omit hours') without adding new semantic detail. With 67% schema coverage, the description provides minimal additional meaning beyond what the schema already conveys.

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 opens with a specific verb and resource: 'Check a requested Bay Area SUV pickup time against current scheduling constraints.' It also differentiates from the sibling quote_ride by stating 'Supply the same route, pickup time and passenger inputs as quote_ride,' clarifying the tool's distinct purpose (checking availability vs. quoting).

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 states the tool uses the same inputs as quote_ride and gives a conditional rule for the 'hours' parameter ('Hourly rides require hours (1–24); other ride types omit hours'). It implies this tool is for checking availability and directs completion at the booking URL, but it does not explicitly state when to use this instead of quote_ride, leaving some inference to the agent.

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