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

Annotations cover read-only/idempotent/open-world, and the description adds substantial non-obvious behavior: a paid endpoint at a stated price, live fetch from data.sec.gov, the two-call x402 handshake, and the critical assurance that the calling agent's own wallet pays and the server never holds funds. That is exactly the kind of operational context annotations cannot express.

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 key facts (paid, resource, forms, output) but the price and payment mechanism are repeated three times across the bracket prefix and body, which costs space without adding information.

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?

For a seven-parameter paid tool with a nested object and no output schema, the description covers return contents (URLs, timestamps), data source, and the full payment lifecycle. Only the routing versus sibling EDGAR tools is missing.

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 the schema. The description restates the payment_header workflow but adds no syntax or precedence detail beyond it (e.g. that cik overrides ticker is in the schema, not here). 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 and resource (retrieve recent SEC filings) with scope: by ticker or CIK, enumerated form types (10-K, 10-Q, 8-K), plus what's returned (document URLs, acceptance timestamps). It does not explicitly distinguish itself from siblings like edgar_fulltext_search or edgar_company_facts, so it stops short of a 5.

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 procedural guidance for the payment flow ('call with no payment_header first'), but never says when to choose this tool over edgar_fulltext_search, edgar_company_facts, or edgar_bundle. Usage is implied by the resource description rather than contrasted with alternatives.

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