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

Annotation readOnlyHint=false could look surprising for a 'get_*' tool, but the description discloses why: it bills on first result return (60P base, 0.5× per extra incomeYear) and re-queries within the validity window are free, matching idempotentHint=true. It also enumerates the outcome state machine (AUTH_WAITING/COLLECTING/RESULT_EXPIRED) and the expiry trigger, so the side-effect profile is fully clear.

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 purpose, then behavior, then the billing note in brackets. Every sentence carries operational meaning, though the pricing formula and status enumeration make it dense; nothing is clearly removable but it is heavier than strictly necessary.

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 compensates by naming the return fields (resultAvailable, status, errorCode, result.cashReceiptDeduction, resultExpiresAt), so an agent knows both what to check and where the payload lives. Nothing needed for a correct async-fetch call is missing.

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?

Only one parameter and schema coverage is 100%, so the format/pattern burden sits on the schema. The description confirms that transactionId must come from the req_cash_receipt_deduction response, but that origin is already stated in the schema description, so it adds little beyond the baseline.

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 (조회한다 – 조회 of approval status and deduction result) and explicitly anchors the tool to the req_cash_receipt_deduction transactionId, cleanly distinguishing it from the sibling that creates the request. An agent can tell this is the polling/result-fetch half of a two-step flow without opening the schema.

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?

Gives an explicit status-driven calling protocol: AUTH_WAITING means wait for phone approval, COLLECTING means re-query with the same ID shortly after, RESULT_EXPIRED means a new authentication request is required. This is exactly the when/when-not guidance an agent needs to avoid mis-calling it.

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