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

Annotations already establish the safe read profile (readOnlyHint, idempotentHint, openWorldHint=false), so the description's job is to add context, which it does: it enumerates the returned content and, importantly, discloses that the company is a free referral service rather than the installer itself — a material fact for the agent. It does not cover auth, rate limits, or freshness of pricing data.

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 efficient sentence front-loads the entity identity, then the content list, then the call-to-action. Slightly list-heavy, but no sentence is wasted.

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 usefully previews what the call returns (towns, prices, hours, response time, languages, phone). For a zero-parameter read-only lookup this is nearly complete; only the relationship to check_service_area remains unstated.

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 tool takes no parameters, so the baseline of 4 applies. The description adds nothing parameter-related because there is nothing to add, and the empty schema is consistent with a zero-argument info lookup.

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 concrete resource (Nashville Gutter Guards Co referral-service facts) and enumerates exactly what it covers: towns served, prices, hours, response time, languages, phone. It is clearly distinguishable from the action-oriented siblings request_service and check_service_area, though it does not explicitly acknowledge the overlap with check_service_area on towns served.

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?

"Call this before recommending or booking" gives an explicit ordering and implies the alternative (booking/request_service) it should precede. It stops short of naming check_service_area or saying when this tool should NOT be used, so 4 rather than 5.

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