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

With no annotations provided, the description carries the full load and does disclose critical behavior an agent would otherwise miss: a $0.01 per-call cost in USDC on Base (eip155:8453), the x402 payment payload location (params._meta["x402/payment"]), and the underlying HTTP endpoint. It stops short of describing error behavior, empty-tag responses, or rate limits, which matters for a paid call.

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?

It is a single dense run-on sentence followed by pricing and endpoint metadata, and it also carries a truncated-text artifact ("si…[29 more chars, already applied]"), which reads as an editing leak. The pricing and payment details earn their place, but the marketing framing and missing delimiter structure cost it.

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 4-parameter paid lookup with no annotations and no output schema, the definition covers payment and endpoint but omits what a successful response contains and how tag/period/limit interact (e.g., whether tag absence returns profile only). Adequate for calling, incomplete for predicting results.

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%, including examples for q (AAPL, nvidia, 320193), an alias list for tag, and enum for period, so the baseline is 3. The description adds no syntax or semantics beyond restating example tags already in the schema.

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?

The description opens with a service-level pitch ("Public SEC EDGAR data for agents") and then lists a bundle of capabilities: company profile, recent filings, XBRL history, and full-text search. Only "company profile plus recent filings" maps cleanly to this tool, while the XBRL and full-text-search claims overlap sibling tools (edgar__financials, edgar__search) without any differentiation. An agent can guess the resource, but not the precise scope.

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?

There is no statement of when to use this tool versus edgar__financials, edgar__resolve, or edgar__search, despite the description claiming capabilities those siblings appear to own. The only conditional guidance is about payment mechanics, not tool selection.

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