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

Annotations already declare readOnlyHint and openWorldHint, yet the description adds substantial context beyond them: the $0.002 USDC per successful call price via x402 on Base/Solana/Arc, the fact that failed calls are not charged, the EDGAR relevance ordering, the 20-result cap, and the 10,000 total being a lower bound. Pricing and cost-incurring behavior are exactly the kind of traits annotations cannot convey.

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 definition is a single dense paragraph that front-loads the purpose and return fields before moving to ordering, caps, filters, and pricing. Every sentence carries information, though the pricing sentence could be visually separated for faster scanning.

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 paid, filtered search tool with an output schema already present, the description covers the remaining essentials: what is searchable, result ordering, the hard 20-result cap, the lower-bound semantics of the total count, the filter dimensions, and the payment model including non-charging of failures. Nothing an agent needs to invoke it correctly is missing.

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 100%, so the schema already documents q, to, from, forms, and limit. The description reinforces the limit cap ('Results are capped at 20') and the forms filter, but adds no syntax or format detail beyond what the schema provides, so the baseline 3 applies.

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 states a specific verb and resource ('Full-text search of SEC EDGAR filings') and enumerates the returned fields (company, CIK, form, filing date, link, file type, 8-K items). It is clear on its own, but it never distinguishes itself from sibling tools such as sec_filings, sec_events, or sec_financials, leaving the agent to infer when this one is preferred.

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 tells the agent how to narrow results ('Filter by form types (e.g. 8-K,10-K) and filing dates') and that results are capped at 20, which implies usage context. However, there is no explicit when-to-use or when-not-to-use guidance, and no alternative sibling is named for the case where full-text search is the wrong tool.

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