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

Annotations cover read-only/idempotent/open-world safety, and the description adds material context beyond them: the data source (SEC EDGAR public filings) and the per-call cost of 0.005 USDC along with the accepted x402 payment rails. Cost and payment-chain requirements are exactly the kind of operational detail an agent needs before calling.

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 use condition, followed by return contents and then source/cost. The middle clause enumerating every returned field is long and partly redundant with the output schema, but overall the prose is dense and purposeful.

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?

Covers purpose, scoping, source, cost/payment rails, and return shape for a three-parameter read tool; an output schema exists, so the extra field listing is a bonus rather than a necessity. Nothing an agent needs to invoke it correctly 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 the schema already documents ticker format, form type, and the 1-50 limit with default 10. The description adds only that 'form' is optional and limited to a single value, plus a few extra examples (S-1, 13F-HR); it adds nothing about limit semantics, so 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 ('Returns the most recent EDGAR filings for a ticker') and enumerates the form types covered, which distinguishes it from the sibling get_sec_8k (single-form) tool. An agent can tell what this retrieves without opening the 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?

Opens with an explicit use condition ('Use when an agent needs a US company's latest SEC filings') and the 'optionally one form type' phrasing clarifies the narrowing behavior. It does not, however, name the sibling get_sec_8k as the alternative for 8-K-specific lookups or state when this tool is the wrong choice.

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