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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds useful behavioral context beyond that: credits are not a currency wallet, the agent must phrase balances as 'you have X credits', and calling the tool refreshes the ChatGPT card. This is helpful and does not contradict the 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 three sentences with no filler. It front-loads the key semantic distinction ('credits are in-app points... not a bank balance') before giving usage guidance and output phrasing rules. Every sentence earns its place.

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 are no parameters, an output schema exists, and the annotations cover the read-only/destructive safety profile. The description adds the missing operational context: when to call the tool, how to phrase the result, and what semantic pitfall to avoid. An agent has what it needs to invoke and use this 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?

The tool has zero parameters and 100% schema description coverage, so there are no parameter semantics for the description to clarify. The zero-parameter baseline applies, and the description does not need to compensate for anything here.

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 title 'Credit balance' and the description clearly identify this as the tool for checking credit status, and the description clarifies that credits are in-app points, not a bank balance. It doesn't use an explicit verb like 'get' or 'fetch' and doesn't contrast itself with sibling tools such as ucode_render_credits, but the intent is still fairly clear.

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 gives concrete guidance: 'After a dashboard or x402 payment, call this so the ChatGPT card refreshes.' This gives the agent a clear when-to-use trigger. It doesn't explicitly state when not to use it or name alternatives, but the context is sufficient for a simple status tool.

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