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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds useful context beyond annotations: it names the data source (FINRA BrokerCheck public API), states that no API key is required, and specifies the return fields. It doesn't describe pagination or rate limits, but those are covered by schema parameters. The description complements rather than contradicts annotations.

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 description is well-structured with a clear first sentence stating the core function, followed by a concise 'Use this tool when' list. It includes the source and API key note at the end. No redundant sentences; every part earns its place. The format is scannable and 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 specifies the return fields (CRD, status, city, state, disclosure flag) and the source. An output schema exists (though not shown), which likely details the return structure. The tool has many parameters, but they are documented in the schema. The description does not mention rate limits or error handling, but for a read-only search tool with an output schema, the provided information is sufficient for an agent to call it correctly.

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's own description does not mention any parameters, but the schema's nested properties (name, rows, start, state, etc.) have rich descriptions with examples. The top-level 'params' property lacks a description, and the signal reports 0% schema description coverage for the top-level wrapper. However, the inner schema descriptions are comprehensive, so the description adds little beyond what the schema already documents. Baseline 3 applies because schema covers the parameters.

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 ('Search'), resource ('FINRA BrokerCheck'), and target ('broker-dealer firms by name'). It clearly distinguishes from siblings like SearchBrokerCheck (likely broader) and GetBrokerCheckDetail by specifying firm-level search. The phrase 'Returns firm CRD, registration status, city, state, and disclosure flag' reinforces scope.

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 includes a 'Use this tool when' section with three concrete scenarios (needing CRD, distinguishing similar firms, building territory maps). It provides clear context but does not explicitly state exclusions (e.g., 'for individuals, use SearchBrokerCheck'). Still, the guidance is actionable and well-aligned with the tool's purpose.

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