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

Annotations already mark this as read-only and idempotent, and the description adds substantial behavioral context: paid datasets never have their row list consulted, rows_withheld reports what was held back, and withdrawn datasets remain refused regardless of sign-up. No contradiction with annotations exists.

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 longer than typical, but it is well-structured with bolded section headers and each section conveys a distinct behavioral fact. It front-loads the core purpose in the first sentence, and the extra length is mostly earned by explaining edge cases and exclusions.

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?

Given the read-only annotations, output schema, and the relatively simple parameter set, the description covers the necessary context: what is free, which tickers work, how paid datasets behave, how withheld rows are signaled, and when withdrawn datasets are unavailable. An agent has enough to decide when and how to call it.

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 for explaining parameters, but it only lists the arg names at the end ('dataset, keyless_eligible, rows') and provides indirect context for keyless_eligible. It does not concretely define what the rows parameter accepts or how it controls the sample, leaving a meaningful gap.

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 opens with a specific verb and object: 'Hand an unregistered caller a short taste of an open dataset, plus where to unlock the rest.' This makes the tool's function immediately recognizable and distinguishes it clearly from query_dataset by explicitly stating 'NOT `query_dataset`.'

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 explicit when-to-use guidance: for unregistered or planless callers who would otherwise receive a flat refusal, and only when someone hits the edge of their entitlement. It also names the alternative, query_dataset, and explains that query_dataset serves entitled callers in full.

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