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

Annotations already declare the tool as read-only, idempotent, non-destructive, and open-world, so the safety profile is covered. The description adds valuable context beyond annotations: pricing per company-period, per-value XBRL source citation, and filing provenance, which materially informs an agent's 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 front-loaded and efficient, with the core capability stated first and the pricing note isolated at the end. It avoids unnecessary repetition of schema details, though it could be slightly tighter.

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 read-only data-retrieval tool with six optional parameters and no output schema, the description covers data source, coverage, metrics, periodicity, identifiers, pricing, and provenance. It is largely complete, though it does not describe pagination or exact row shape beyond the sources fields.

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 input schema has 100% description coverage, so the baseline is 3. The description reinforces key parameter concepts (ticker or CIK, annual or quarterly, 5-20 years) but does not add syntax or constraints beyond what the schema already documents.

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 verb and resource: 'Get clean financial statements of any US-listed company from the SEC's own XBRL data.' It enumerates the covered statement types and distinguishes the tool from parsing filings, making its purpose immediately clear.

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 gives a use case ('For analysts, finance apps and AI agents that need a company's numbers over 5-20 years without parsing filings') but does not explicitly name alternatives or exclusions versus siblings like sec_filings_feed or esef_annual_reports. Usage is implied rather than fully guided.

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