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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds a genuinely important behavioral fact the annotations do not: the $0.004 USDC x402 per-call cost, which an agent must weigh before invoking. It still omits response shape and pagination/limit behavior.

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?

One dense sentence with the counts front-loaded, followed by the pricing clause. Nothing is wasted, though the single long sentence packs geography, industry, output measures and pricing into one breath rather than structuring them.

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 correctly carries the return-value burden by naming the metrics returned, and it covers geography, industry filter and cost. It leaves the zero-required-parameter default behavior and the limit parameter's effect unspecified, a minor gap.

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 80%, so the schema already documents zip, near, level and industry with examples. The description restates the geography levels and the keyword-or-NAICS industry syntax but adds no new syntax or defaults, so the baseline 3 applies.

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+resource (count businesses) with the exact scope (US county, state or ZIP) and enumerates the returned measures (establishments, employees, payroll, average pay, per-capita business density). An agent can distinguish this from siblings like demographics, economy, or company without opening the schema.

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 'for market sizing and competition checks' gives explicit usage context, which is more than implied. However, it names no alternative tool and states no when-not condition, so it stops short of the top score.

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