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

Annotations already cover the safety profile in full (readOnly, idempotent, non-destructive, closed-world), so the bar is low. The description does add real value by disclosing that only a restricted slice of businesses is searchable (top 5 / state #1), which warns of false negatives, but it says nothing about match behavior, ambiguity, or what happens with zero or multiple matches.

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 front-loaded sentence: verb, resource, search keys, then the scoping constraint. No filler, nothing repeated from the schema or annotations.

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 simple read-only two-parameter lookup with no output schema, the description covers purpose and scope but omits return shape (single match vs list) and no-match behavior. Those gaps matter because 0% schema coverage leaves parameter and result semantics otherwise undocumented.

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 description coverage is 0%, so the description must carry the burden; 'by name or domain' does establish what each of the two parameters means and implies a one-of choice. It does not address the notable fact that neither parameter is required, nor what happens if both are supplied.

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 ('look up') and resource ('a business') plus the exact data scope it searches ('publicly shown listings – national top 5 and state #1s'). That scope detail distinguishes it from siblings like get_national_top5 and get_state_leader, though it never names them explicitly.

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?

The phrase 'by name or domain' implies the invocation context and the scope parenthetical hints at how this differs from the top-5/state-leader tools. But there are no explicit when-to-use/when-not-to-use statements and no named alternatives, leaving the agent to infer routing from sibling names.

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