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

Annotations already declare readOnly, idempotent, and non-destructive behavior, so safety is covered. The description adds genuine domain context beyond the annotations: it discloses the business rule that online booking is gated on service-area membership. It does not describe the return shape, but adds real behavioral value.

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?

Two tight sentences with zero filler, and the core purpose is front-loaded ahead of the booking constraint. Every sentence earns its place.

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 single-parameter, read-only lookup with no output schema, the definition is largely complete: it conveys purpose and the downstream booking constraint. It is slightly short on what the check returns (presumably a boolean) and how ambiguous city names are handled, but nothing critical is missing.

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% and the 'city' parameter is already documented with a concrete example ('Solon' or 'Solon, OH'). The description adds nothing about parameter format or matching semantics, so the baseline of 3 for a fully-covered schema is appropriate.

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 check ('Whether Riverview regularly serves a city') tied to a named resource, and the name/schema make the verb+resource unambiguous. It does not explicitly differentiate itself from siblings like book_walkthrough, though it hints at the relationship, so it stays below 5.

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?

Usage is implied rather than stated: the note that 'Walkthroughs can only be booked online for cities in the service area' suggests calling this before book_walkthrough, but there is no explicit 'use this when...' guidance or named alternative. The link to the sibling is inferable but not spelled out.

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