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

Beyond the readOnly/idempotent/non-destructive annotations, the description discloses what is actually returned (ranked candidates with reasons for/against), the ranking signals used, and non-obvious behavior: sites sharing a phone number or near-identical homepage text are collapsed into one network. It even notes the result is signed.

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?

The when-to-call trigger is front-loaded, and the dense parenthetical signal list earns its space given no output schema exists. It is a single run-on sentence, which makes it harder to scan than it could be, but there is little wasted text.

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 carries the full burden of explaining return values and does so thoroughly: ranked candidates, reasons for and against, deduplication behavior, and signing. An agent has everything needed to call and interpret the result.

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?

With schema coverage at 100%, the baseline is 3, but the description adds real meaning: it clarifies the either/or relationship between the domains mode and the trade+city mode, and tightens the domains bound to 2-10 (schema only says 'up to 10').

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+resource: choosing WHICH business or site to cite, recommend or call, and it names the verification source (CrawlCheck) driving the output. It is clearly distinguishable from siblings like scan_domain or preflight, though it never explicitly frames them as alternatives.

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?

It gives a clear when-to-use trigger ('Call when choosing WHICH business or site to cite, recommend or call') and two distinct input modes: candidate domains vs trade+city for a measured market. It stops short of naming when NOT to use it or which sibling to pick instead.

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