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

With annotations declaring readOnlyHint and openWorldHint, the description adds meaningful behavior beyond them: 60-second upstream caching, inclusion of 8-K item codes, accession numbers for pinning, and a $0.01 per-call cost. This is valuable operational context for an agent deciding whether and how often to call the tool.

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?

Four sentences total, each carrying useful information: purpose, target use case, caching behavior, data payload highlights, and cost. There is no filler or repetition from the 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?

The tool has no output schema, so the description partially compensates by naming key response features (8-K item codes, accession numbers). It covers caching, filtering, and cost. It does not fully describe the response shape or pagination, but for a simple pollable feed with two parameters, it is sufficiently complete.

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 baseline is 3. The description adds only that the form filter is optional and that the feed is market-wide; it does not add new meaning for the limit parameter beyond what the schema already states. This is adequate but not a differentiator.

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?

Description clearly identifies a market-wide SEC filing feed, establishes its real-time nature, and distinguishes it from sibling tools like recent_filings and edgar_search by emphasizing market-wide scope and 'as they land' behavior. It also adds differentiating details like 8-K item codes and accession numbers.

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?

The description explicitly states the intended use case: 'Built for monitoring agents that poll' and provides the 60-second cache as a practical polling consideration. It also clarifies the optional form-type filter. It does not explicitly name alternatives or when not to use this tool, but the intended context is clear.

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