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

Annotations already cover read-only, idempotent, non-destructive and open-world. The description adds genuinely new behavior: per-row XBRL tag and SEC accession/URL citations, and a stated price of $0.002 per screen-row, which matters because maxResults is billed. It does not describe pagination or result ordering limits beyond the argument docs.

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?

Three short paragraphs: capability plus examples, audience, then provenance and price. Front-loaded with the screening verb, and no sentence is 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?

With eight parameters, no output schema and a per-row charge, the description does the right extra work by disclosing citation behavior and pricing. Only gaps are return cardinality/pagination and any note that results are limited to filers with XBRL data for the given period.

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?

Even though schema coverage is 100% (baseline 3), the description adds concrete meaning on top: it maps natural-language screening intent onto the filter/sortBy/metrics triple ('revenue over $10B and net margin above 20%', 'top 20'). It also frames the crop of metric names as revenue, profit, margins, cash flow and balance sheet, so the agent understands the enum's scope without scanning all 36 values.

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 ('Screen every US company that files with the SEC') scoped to financial metrics, with two concrete query examples. It implies bulk screening versus the single-company sibling sec_company_financials but never names or contrasts that sibling explicitly.

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 example queries ('revenue over $10B and net margin above 20% in 2025', 'top 20 by operating cash flow') and the audience line ('analysts, finance apps and AI agents') imply when the tool fits. There is no explicit when-not guidance or pointer to alternatives such as sec_company_financials for one company or sec_filings_feed for filings.

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