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

Goes well beyond the annotations by disclosing the billing model (charged on first result, free re-queries within the validity window), the full status state machine, and the need to inspect resultAvailable/status/errorCode. The charge-on-first-call behavior actually explains why readOnlyHint is false despite this being a lookup, and nothing contradicts idempotentHint=true.

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-loads the core action, then status handling, then cost, then return contents, then expiry. Every sentence carries operational information; even the enumeration of result sections serves the point that only the products chosen at request time are returned.

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?

No output schema exists, so the description carries the full burden of explaining return values, and it does: it names the status/error fields to check, the possible result.* sections, and the expiry error. An agent has everything needed to poll correctly and to know when to re-request.

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 schema already documents the lowercase 32-hex transactionId and its origin in the same-product req_hometax_bundle response. The description restates that provenance but adds no new syntax or format detail beyond the schema, so baseline 3 applies.

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+resource: retrieving approval status and personal national-tax integrated lookup results by transactionId. It explicitly ties itself to the sibling req_hometax_bundle as the source of the ID, making the request/result pair unambiguous against the many other req_* 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?

Gives concrete branch-by-branch guidance: AUTH_WAITING means wait for phone approval, COLLECTING means re-query with the same ID after a pause, and after resultExpiresAt the agent gets RESULT_EXPIRED and must file a new authentication request. It names the exact condition that routes the agent to the sibling req_hometax_bundle.

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