Check listing status and corporate actions

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

Annotations cover read-only and open-world traits, and the description adds substantive domain behavior: splits corrupting per-share figures, reverse splits distorting cheapness, and delisted tickers persisting in EDGAR. It does not describe the actual response payload, but the added context is genuinely useful.

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?

Front-loaded with the purpose, then two concrete failure examples that justify the call. Efficient overall, though the two illustrative sentences are somewhat lengthy for the core payload.

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 no output schema, the description does not specify the exact return shape (splits, dividends, delisting status), which is a gap. Otherwise it gives enough rationale and parameter guidance for an agent to invoke it correctly.

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 schema already documents all three parameters well. The description reinforces the `since` semantics ('Pass the balance-sheet period end as `since`') but adds little beyond the schema's own wording, meriting the baseline 3.

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 (Check) and resource (listing status and corporate actions for a ticker against Polygon reference data), and the contrast with a 'ratio' plus the EDGAR index implicitly distinguishes it from sibling analysis tools.

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?

Explains the two failure modes it catches (split between balance-sheet date and today, delisted tickers in EDGAR) and instructs to pass the balance-sheet period end as `since`, giving clear context for use. It lacks an explicit when-not-to-use or named alternative sibling.

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