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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description contributes the fact that the result reflects payment settlement rather than merely a record's existence, which is useful, but it says nothing about caching, polling freshness, or idempotency.

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?

A single front-loaded sentence with zero filler; nothing is repeated from the schema or annotations.

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?

There is no output schema, so the description is responsible for explaining what the check returns (e.g. paid / unpaid / pending, and any error for an unknown id), yet it never does. For a status-check tool that an agent will likely poll, missing return and polling semantics is a real gap.

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 both parameters are documented inline, including that topup_id comes from top_up, so the schema does the work. The description adds no meaning about topup_id format, lifetime, or the passport_token fallback.

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 plus the exact attribute being checked ("whether a top-up was paid"), which distinguishes it from the sibling top_up that initiates payment. It doesn't name top_up explicitly as its counterpart, so it stops short of a 5.

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?

No guidance on when to call this versus top_up or the other payment siblings (buy, claim_refund), and no mention of whether it is meant to be polled after top_up or called once. The agent must infer the entire workflow from the parameter's schema text.

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