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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true; the description reinforces this with 'Public records, read-only' and, more valuably, discloses an interpretive caveat: amount sold is the filing-date snapshot, not final fund size or AUM, and must be cited with the filing date. It doesn't mention rate limits, error behaviour or what happens when a CIK exists but no Form D does.

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 action and lookup keys, then the field payload, then the caveat. Every clause carries information an agent would otherwise have to infer, and there is no filler.

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?

An output schema exists and the annotations cover the safety profile, so the description's job is largely scoping and interpretation, both of which it handles. The gaps are the undocumented companyId parameter and the tension between the stated 'by CIK and accession number' requirement and the schema declaring zero required parameters.

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 coverage is 33% and the description supplies meaning for only two of the three parameters (cik, accessionNumber), saying nothing about companyId or why a UUID wrapper is accepted alongside a CIK. Format/pattern details live in the schema, so the description adds modest value over it rather than compensating for the sparse coverage.

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 (reads), a specific resource (one Form D), the source system (EDGAR) and the exact lookup keys (CIK and accession number). It also enumerates the payload, so an agent can tell it apart from the broader filing-search sibling without opening the 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?

The 'one Form D ... by CIK and accession number' framing implies this is the single-record fetch used after a search, but no alternative such as fundraising_search_sec_filings is named, and no exclusion or prerequisite (e.g. 'must already know the accession number') is stated outright.

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