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

Annotations already cover safety (readOnly, idempotent, non-destructive), and the description adds real operational context on top: the 20-notice cap, the 90-day lookback, the possibility of an empty result that is still charged, and the pricing model (first cached result free, otherwise $0.005 USDC via x402). This is exactly the beyond-annotation detail an agent needs.

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 purpose and the returned fields, then the lookback/cap limits, then pricing. Dense but each sentence carries information; the pricing and disclaimer sentences are somewhat ancillary but justifiable for a paid endpoint.

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 enumerates the returned fields (who intends to sell, units, filer market-value estimate, broker, approximate sale date, Rule 10b5-1 dates), discloses coverage limits and empty-result behavior, and explains payment — covering everything needed to call and interpret the response 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 description coverage is 100% — ticker format and the x_payment challenge/retry flow are both documented in the schema itself. The description adds no parameter-level syntax or constraints 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 ('Read') and resource (SEC Form 144 notices of proposed insider sales) scoped to a US ticker, and implicitly separates it from the sibling otto_insider_trades by explaining Form 144 precedes the Form 4 executed-trade filing. An agent can identify this as the pre-trade intent feed rather than the executed-trade feed.

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 clear context for when this applies — pre-execution intent notices, distinct from executed trades — and warns a notice may never be executed, which is genuine usage guidance. It does not name the alternative tool (otto_insider_trades) explicitly as the counterpart, so it stops short of a full routing instruction.

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