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

No annotations are supplied, so the description carries the burden. 'Check whether' implies a non-mutating boolean lookup, which conveys the basic safety profile, but it says nothing about the result shape, how an unrecognized district is reported, or whether partial/alternative name matches are handled.

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?

A single sentence that front-loads the action and appends the one input caveat that matters, with 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?

For a one-parameter lookup with no annotations and no output schema, most of what an agent needs is present. The notable gap is result semantics — whether the answer is a boolean, a list of served areas, or an error for unknown districts — which the description never addresses.

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 0% (only a maxLength constraint on 'area'), so the description must compensate — and it does, specifying that the parameter is a district or settlement name and explicitly not a street address. That is meaningful disambiguation beyond the schema; only the 200-character limit and format expectations remain undocumented.

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: 'Check whether the laundry courier serves a district or settlement.' That distinguishes it from the other lookups (prices, hours, FAQ, slots, business info). It stops short of naming any sibling explicitly, so it is clear but not maximally differentiated.

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?

Implicit usage is clear (verify coverage for an area before ordering), and it adds a valuable input constraint: 'give the district/settlement name, not a street address.' However, it offers no when-not guidance, no mention of what to do for ambiguous or partial area names, and no pointer to an alternative tool.

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