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

No annotations are provided, so the description carries the full burden. It usefully discloses the 100-entry cap, which is a behavioral constraint beyond the empty schema, but it does not state that the operation is read-only or mention any permission or rate-limit considerations.

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 seven-word fragment with no wasted words, and the most important information (balance and recent ledger entries) is front-loaded.

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 should explain return values more fully. It states that balance and the last 100 ledger entries are returned, but it omits details like entry fields, ordering, or whether the balance is current at call time.

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, which matches the baseline expectation of 4. The description does not need to explain parameter semantics and appropriately focuses on output content.

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 clearly states the tool returns the credit balance and the last 100 ledger entries. This is specific about the resource and output, though it lacks an explicit verb and does not differentiate itself from siblings like credit_packs or credits_checkout_url.

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?

There is no guidance on when to use this tool instead of alternatives such as credit_packs or credits_checkout_url. The intended use (viewing balance/history) is implied only by the description of returned data.

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