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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false. The description adds valuable behavioral context beyond that: price ($0.02 USDC via x402 on Base), omitted narrative/address fields, SEC EDGAR data source, and no-warranty/as-is terms. It still does not discuss rate limits or response-size behavior.

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?

The description is compact and front-loaded: it opens with the data resource and scope, then lists returned fields and omissions, then pricing and disclaimers. Every clause adds useful context with no filler.

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 two-parameter read-only tool with full schema coverage and clear annotations, the description covers what is returned, what is omitted, data source, pricing, and warranty limits. No output schema exists, and the return fields are sufficiently enumerated for correct invocation.

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%, with both ticker and days fully documented including default and max values. The description mentions ticker and last N days but adds no syntax or format details beyond what the schema already provides, so baseline 3 is appropriate.

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 states a specific resource and scope: SEC Schedule 13D/13G filings for a ticker over the last N days, and lists the returned fields. This clearly distinguishes it from siblings like get_insider_trades and get_8k_events without needing their schemas.

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 implies usage by saying it returns filings on a ticker in the last N days, but it does not explicitly say when to use this versus get_insider_trades or other siblings, nor does it state when not to use it. The informational-only disclaimer is not usage guidance.

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