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

No annotations, so the description carries the full load; it does add valuable non-schema behavior: newest-first ordering and a per-call price of $0.003 USDC via x402 on Base, which signals a paid metered endpoint. It says nothing about pagination limits beyond the schema, error/empty behavior, or what 'as filed' implies about restatements.

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?

A single dense sentence that front-loads what is returned and closes with the payment model. The parenthetical field enumeration is long but earns its place since there is no output schema.

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?

Listing the returned fields compensates for the missing output schema, and the price disclosure covers the payment dimension. However, with six parameters and no annotations, the description still omits guidance on ticker vs CIK selection, limit behavior, and when this endpoint is the right choice.

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 every parameter is already documented, including concept examples and unit filters. The description only echoes the form/unit filters and the output field list, adding no semantics beyond the schema; 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 resource and verb: values of one XBRL concept as filed, with the exact returned fields enumerated. The opening 'Same as POST /facts with query strings' is a REST-ism that doesn't map cleanly to a sibling tool name, so differentiation from edgar_facts/edgar_financials is left partly implicit.

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?

Mentions optional form and unit filters but never says when to choose this over edgar_facts, edgar_financials, or edgar_filings. An agent gets no decision rule beyond the fact that a concept is required.

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