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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive, so safety is covered. The description adds valuable behavioral detail beyond that: it does not send a message or create a booking, and it discloses auth requirements for each path (SMS verification plus a private short-lived proof for history; SMS code and detail review for booking). The only gap is what happens after the form is submitted.

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 sentences, front-loaded with the usage trigger and then the behavior and auth requirements. No filler, though it could be slightly tighter by merging the booking/history requirement sentences.

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?

Given one optional enum parameter, full schema coverage, and an output schema, the description covers when to invoke, what the tool does and does not do, and per-path auth requirements. It omits post-submission behavior and how it relates to sibling booking tools, which prevents a 5.

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 enum already documents 'booking' vs 'history'. The description mentions the two paths but doesn't add syntax or defaults beyond the schema, so baseline 3 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 names a specific verb/resource ('book Johnson Bros. service or search their own past visits') and clarifies what the tool actually renders – a compact card that expands into a customer form. It distinguishes itself from siblings like request_booking and search_service_history by describing an interactive UI surface rather than a backend action.

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?

Clear when-to-use framing ('Use this when the customer wants to book... or search their own past visits') and it separates the two modes. It doesn't explicitly rule out when NOT to use this versus siblings like request_booking or customer_lookup, which keeps it short of a 5.

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