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

Beyond the readOnly and openWorld annotations, the description discloses the per-call cost and payment method (credit key or machine payment), which are crucial behavioral details not captured elsewhere. It also notes the revenue concept discrepancy, adding transparency about potential empty results.

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 concise, with a clear main sentence, a useful note, and a cost/payment sentence. It avoids unnecessary verbosity and is well-structured, though the revenue note could be seen as slightly tangential.

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 covers the core functionality, cost, and a data nuance, but lacks specifics such as the number of periods returned, handling of missing data, or output format. Since there is no output schema, these details would be valuable for a complete understanding.

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 provides full coverage for both parameters. The description adds context about 'as-reported' and 'recent periods' but does not elaborate on the semantics of the parameters themselves beyond the revenue tip, which is a specific example rather than general parameter guidance.

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 fetches an as-reported XBRL financial concept for a company across recent periods, which is a specific verb+resource. It distinguishes from siblings like verify_financial_claim or who_holds by focusing on raw XBRL data, though it doesn't explicitly contrast with alternatives.

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 practical tip about revenue concept alternatives and mentions cost and payment requirements, implying when to use it. However, it does not explicitly state scenarios where other tools would be preferred, so it falls short of the highest level.

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