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

Annotations already declare the safe read-only, idempotent nature, so the description adds useful context beyond them: times are local to the tour, availability may be unknown, and the agent should not guess when no times are listed. It does not describe return structure or permission requirements, but it covers the key behavioral caveat for this tool.

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 front-loaded with the core purpose and local-time caveat, then immediately gives operational guidance and a fallback. Every sentence contributes to correct tool selection or invocation.

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 identifies the key return content (open departure times and booking status) and warns about unknown or empty results. It is complete enough for an agent to choose and call the tool, though a fuller return-shape description would make it stronger.

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 has 100% description coverage for tour, date, and party_size, so the description does not need to duplicate parameter details. It reinforces the one-tour/one-date scope and local-time meaning, but adds little 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: retrieving open departure times and booking status for one tour on one date from the American Ghost Walks booking system. It clearly scopes the operation to a single tour/date pair, which distinguishes it from siblings like search_tours and get_tour_details.

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?

It gives explicit when-to-use guidance: check this before telling a guest a time is open. It also names the alternative behavior when availability is unknown or no times are listed: send the guest to the booking link instead of guessing.

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