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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety is covered. The description adds genuine non-annotation context: that returned slots do not guarantee party capacity or exact-address coverage, which changes how an agent should interpret results. It says nothing about rate limits or empty-result behavior, keeping it out of 5 territory.

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 sentences, both front-loaded: the action and its ordering constraint first, then the interpretive caveat. No filler, no restatement of the title.

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?

An output schema exists, so return values need no explanation. For a read-only, three-parameter availability probe, the description supplies the ordering context and the interpretation caveat that an agent actually needs to use the result correctly.

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 67% and the schema itself documents serviceId and optionId only as 'Returned service ID'/'Returned option ID, if needed.' The description reinforces the key semantic that both are values returned by earlier calls, and frames optionId as optional in context. It adds meaning beyond the raw schema without detailing date formats (the schema already handles that).

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 ('Check a returned WellFred service and option on a specific date') plus the sequencing constraint 'before discussing reservation times'. The word 'returned' signals the IDs must come from a prior tool call, which partially separates it from siblings like wellfred_search_services, though no sibling is named outright.

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?

Gives a clear when: before discussing reservation times, i.e. as a validation step ahead of booking. It also flags a boundary ('Slots do not prove party capacity or exact-address coverage'), which is a when-not condition. It stops short of naming alternatives such as wellfred_prepare_booking or wellfred_offering_detail, so no explicit routing.

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