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

With no annotations, the description carries the full burden of behavioral disclosure. It reveals the output limit (up to 20 records), the JSON format, and all returned fields (callsign, licensee_name, frn, service, status, grant_date, expired_date, cancellation_date). It omits details like matching semantics or error behavior, but for a read-only lookup this is strong disclosure.

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?

Three sentences with no waste: the first states the core action and input, the second covers optional filtering, and the third specifies the exact output shape. The most important information is front-loaded.

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?

The description is self-sufficient for a moderate-complexity search tool: it covers the searchable identifiers, filter options, result count, and every returned field. Even with no annotations, no output schema, and zero schema description coverage, an agent can call the tool correctly. The only notable gap is explicit sibling differentiation.

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 compensate. It gives q real meaning (company/licensee name, call sign, or FRN) and clarifies that service, status, and limit are filters. Yet it does not explain the meaning of valid status/service codes, leaving the regex patterns as the only hint.

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 ('Look up'), a clear resource ('FCC radio licences'), and the kinds of identifiers q accepts (company/licensee name, call sign, or FRN). This distinguishes it from sibling tools like fcc_company, fcc_coverage, and fcc_stats.

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 description makes clear when to use the tool (when searching licences by name, call sign, or FRN) and mentions optional service, status, and limit filters. However, it provides no explicit guidance about when not to use it or how it compares to sibling tools.

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