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

Beyond the readOnlyHint/openWorldHint annotations, the description discloses the pricing model ($0.002 USDC per successful call, x402 on Base, Solana or Arc, failed calls not charged), which is important behavior an agent cannot infer from annotations. It also discloses the data limitation that offering amounts are not parsed. Minor gap: no mention of pagination/result-cap behavior even though the limit parameter hints at it.

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?

Front-loaded with what the tool returns, then the scope limitation, then alternatives, then price — a sensible order for an agent scanning for relevance. The pricing sentence is long and parenthetical-heavy, but each clause (per-call price, payment rails, no charge on failure) carries distinct information.

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 an output schema present and 100% parameter coverage, the remaining burdens are cost, coverage limits, and sibling disambiguation — all of which the description handles explicitly. An agent has enough to decide relevance, call it correctly, and anticipate the charge.

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 two parameters (limit with its 1–20 range and default, and query with example terms) are already fully documented. The description mentions filer-name/text matching only indirectly via 'filer name' in the field list and adds no syntax or semantic detail beyond the schema, so 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 names a specific resource (SEC Form D filings, private securities offerings under Reg D) and its source (EDGAR's public search index), then enumerates the returned fields: filer name, CIK, filing date, state, accession number. It also explicitly states the scope boundary 'Lists filings only', which lets an agent distinguish it from a filings-detail tool without opening a schema.

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 explicit routing rules to two named siblings with the conditions that select them: finance_sec_form4 for recent Form 4 insider filings for one company CIK, and finance_sec_iapd for Investment Adviser Public Disclosure searches. It also states an exclusion ('offering amounts are not parsed'), which prevents a misuse case where an agent expects fundraising amounts.

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