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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is known. The description adds that the tool is FREE and lists paid siblings, which is useful, but it discloses nothing about freshness, limited ticker coverage, or what the sample actually contains.

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?

Two sentences, front-loaded with 'FREE.' and the usage trigger. The alternative-tool list is dense but earns its place as routing guidance; nothing is padded.

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 should clarify the return contents, but it only says 'sample.' An agent cannot tell from the description alone that it gets AAPL/MSFT/NVDA revenue, net income, and the newest SEC filing – that detail is only in the title.

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?

Zero parameters, so the baseline is 4. The description correctly implies no arguments are needed, though it does not explicitly say the tool takes no input.

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 says only that this returns 'a sample of US stock data' and never names the tickers or metrics it covers; the specificity lives in the title, not the description. It does distinguish itself indirectly by pointing to paid tools that 'cover any ticker,' implying this one is a narrow free sample.

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 gives an explicit use case ('when an agent wants a sample of US stock data') and names the four paid alternatives with prices for full coverage. It stops short of an explicit when-not condition, but the routing intent is clear.

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