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

Annotations already establish readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds meaningful behavioral context by naming the data source (SEC EDGAR XBRL), the filing window (most recent 10-K), the specific metrics compared, and the flagging behavior for non-matching claims. No contradiction with annotations.

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 a single dense sentence that front-loads the core action and then efficiently lists the source, filing type, and metrics checked. Every clause contributes, though the long em-dash list makes it slightly harder to parse than a structured two-sentence version would be.

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 single-parameter, read-only tool with no output schema, the description is largely complete: it specifies what input is expected, what data it is checked against, which metrics are validated, and what the tool does with discrepancies. It does not detail return formatting or edge cases like missing filings, but the core invocation context is clear.

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%, and the schema already describes the text parameter as 'draft text to check, with $TICKER cashtags.' The description reinforces this with the example '$AAPL' and clarifies that the text is financial writing, but it does not add substantially new parameter-level meaning beyond the schema.

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 names a specific verb ('Check'), a concrete resource (SEC EDGAR XBRL company-facts data for the most recent 10-K), and a clear scope ($CASHTAG-style ticker mentions in financial writing). It lists the exact metrics checked and the outcome (flagging mismatches), which clearly differentiates it from the many other check_* sibling 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?

The description clearly implies when to use the tool: when a user has a draft financial text containing $TICKER cashtags and wants verification against filed SEC figures. It does not explicitly state exclusions or alternatives, but the use case is unmistakable and specific enough for an agent to route correctly.

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