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

With readOnlyHint=true already declaring the safety profile, the description adds the upstream REST endpoint (GET /stock/profile2) and enumerates the returned payload, which is valuable given there is no output schema. It still omits any note on identifier resolution behaviour or error cases when an identifier matches nothing.

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 compact sentences: what it returns, the identifier requirement, and the backing endpoint. The resource and identifier constraint are front-loaded, and nothing is padding.

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 lookup with no output schema, the description covers the returned fields and the required identifier input, which is enough to call it correctly. Minor gaps remain around behaviour when multiple or zero matches occur, but the essentials are present.

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 100%, so the baseline is 3, but the description adds a real constraint the schema does not encode: required is empty, yet the tool needs at least one of symbol/isin/cusip, and the description says so explicitly. That prevents an agent from calling it with no arguments.

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 resource (company profile) and enumerates the fields it returns — name, country, currency, exchange, industry, market cap, shares outstanding, IPO date, logo — which separates it from finnhub_quote and finnhub_basic_financials without naming them. It is clear what the tool is, though it never explicitly contrasts itself with those siblings.

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 gives a usage constraint ('provide at least one of symbol, isin or cusip') but offers no guidance on when to pick this tool over finnhub_basic_financials, finnhub_symbol_search or finnhub_quote. Usage is implied by the field list rather than stated.

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