SEC filings API service info (free)

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

Annotations already declare readOnlyHint=true and openWorldHint=trueable, and the description adds that it is free, that it lists endpoints/prices/payment details, and that it should be used before paid calls. This is useful context beyond the annotations, without contradicting them.

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?

Two sentences with no filler: the first states what the endpoint is and what it returns, the second tells the agent when to use it. Everything earns its place.

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 zero-parameter, read-only info endpoint, the description fully covers what the agent needs: the resource, the included content (pricing, payment network, wallet address), and its intended position in the workflow (use before paid calls). No output schema is needed for such a simple discovery endpoint, and the annotations already confirm safety.

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?

The tool has zero parameters and 100% schema coverage, so the baseline is already strong. The description adds that the call needs no arguments beyond indicating it is a discovery endpoint to check first, which is sufficient for a parameterless tool.

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 clearly identifies a specific verb ('describes') and resource ('available SEC EDGAR data endpoints, their prices, payment network and wallet address'). It also labels the endpoint as a free discovery endpoint, which distinguishes it from the paid data endpoints it describes.

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?

Explicitly instructs the agent to use it first to check pricing before calling a paid tool. This gives clear when-to-use guidance and implies it should not be used for actual data retrieval, which is handled by sibling tools.

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