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

Annotations already declare read-only, idempotent, non-destructive and closed-world, so safety is covered. The description adds genuinely useful behavior: default newest-first ordering, what each mode returns, that dashes in the accession are optional, and the search scope across published records. It stops short of auth/permission or pagination/rate-limit behavior, so not a 5.

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?

Content is dense but nearly every clause earns its place, since with no output schema the enumerated return fields (form types, filing date, EDGAR index URL, document URL, uses) are load-bearing. The cost is that it is delivered as two sprawling sentences rather than structured mode blocks, which hurts scannability.

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 no output schema, the description fully carries the burden of describing returns in both modes, including what 'every use' means and that full narrative/events text is returned for a single accession. Combined with the 100% schema coverage and the annotations, an agent has everything needed to call it correctly.

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 100%, so the baseline is 3 and the schema already documents all three parameters. The description goes beyond it by decoding an accession number (filer CIK, year, sequence) and clarifying that the format is the SEC's permanent ID and that dashes are optional, which meaningfully improves how the agent supplies the value.

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 resource (SEC filings behind a company's data) and cleanly splits the two modes: list every accession cited when `accession` is omitted, versus full detail on one filing when it is given. It also names the sibling `get_figure` and the condition that selects it, so an agent can route without opening either 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?

Explicit when-to-use branching on the `accession` parameter, plus the scope rule that all published records are searched unless `record` narrows it. It ends with a direct alternative routing ('For the sec.gov line behind one figure, use get_figure'), which is exactly the differentiation the sibling list demands.

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