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

Annotations already carry the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description adds substantial non-obvious behavior: the full status taxonomy (confirmed/not_found/partial/out_of_scope/out_of_coverage), the itemised claimed-vs-filed diff on partial matches, the ±3 filing-day date tolerance, the always-disclosed coverage window, and the Rule-2 constraint that item codes are parsed from the filing rather than inferred from prose.

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 the core action and claim shape, then enumerates outcomes efficiently. The dense em-dash clauses make the status list slightly harder to scan than it needs to be, but there is little wasted text.

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?

No output schema exists, so the description must explain returns — and it does, enumerating each status and what accompanies it (source filing plus link on confirmed, itemised diff on partial). Combined with the coverage-window disclosure and scope exclusion, an agent has everything needed to call and interpret the result.

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 all seven parameters are already documented in-schema, including the CIK format, ISO dates, accession format, and comma-separated item codes. The description references the cik/company/accession grouping but adds no syntax or format detail beyond the schema, 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?

States a specific verb (verify a claim) against a specific resource (SEC Form 8-K filing record), and names the exact claim shape it accepts (registrant + item codes + timeframe). This is clearly distinguishable from the sibling verify_* tools that target 13F/13D/insider purchases.

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?

Gives strong in-scope context and explicitly carves out out_of_scope claims (meaning/materiality of the filing body), which functions as a when-NOT-to-use statement. It doesn't name sibling tools or say when to prefer a related verification tool, so it stops short of a 5.

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