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

Annotations already establish read-only, non-destructive, open-world behavior. The description goes well beyond them: it discloses the pure-publisher posture, that financials are issuer-reported and generally unaudited, that fields are null where a variant omits them, and the C → C-U → C-AR chain structure — genuinely useful context an agent needs to interpret results.

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?

Dense but well front-loaded: what it returns first, then usage, then enum mapping, then exclusions and caveats. Every sentence carries information, though the block is long enough that a tighter edit is conceivable.

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 carries the full burden and does so — it enumerates the returned fields (issuer, portal, offering terms, financials, employee count) and flags the caveats that affect interpretation. Nothing material is missing for correct invocation.

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. The description adds real value beyond the schema: it maps filing_type enum values to form families, explains the cik + sort asc pattern for reading filing chains, and notes null-semantics for financial fields. Minor gap: it references is_withdrawal, which is not an exposed parameter.

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 the specific resource (SEC Form C filings / Reg CF offerings), the covered period (2016-05→present), and the exact record shape. It explicitly names and excludes sibling form families (Reg A+ via get_reg_a_offerings, Reg D via get_private_placements), so an agent can disambiguate 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?

Gives an explicit 'Use this when the user asks about:' list of concrete intents (portal market share, early-stage issuers in a state, revenue/assets of a crowdfunding company) and routes alternative form families to named sibling tools. Both when-to-use and when-not-to-use are present.

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