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

The readOnlyHint annotation already establishes the safe, read-only nature. The description adds the REST endpoint, but does not mention rate limits, authentication, or response structure. The phrase 'and more' is vague, providing limited added transparency beyond 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 two sentences, front-loads the purpose, lists key fields, and states the input rule and endpoint. There is no filler or redundant information, making it highly efficient.

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 tool is simple with three identifier parameters and no output schema. The description covers the main output fields and the input requirement, but does not specify the exact return shape (e.g., single object vs. null). This is adequate but leaves a small 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?

The schema already documents each parameter and indicates they are alternatives. The description adds the crucial constraint that at least one identifier is required, which is not expressed in the schema's optional fields. This goes beyond the structured data.

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 clearly states it returns a 'General company profile' and enumerates specific data fields (name, country, currency, exchange, industry, market cap, etc.), distinguishing it from siblings like finnhub_quote or finnhub_basic_financials. The REST endpoint reference further clarifies the operation.

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 provides a clear input requirement ('Provide at least one of symbol, isin or cusip') and the field list implies it is for static company data. However, it does not explicitly compare against alternatives, so it misses the 'when-not-to-use' guidance.

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