Show Account

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so safety is covered. The description adds useful operational context beyond that: report the balance in USD and surface auto-recharge only when enabled, which shapes how results should be presented rather than repeating the annotation claims.

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?

Three short sentences in a deliberate order: what it does, when to call it, how to report the result. No filler, and the core purpose 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 an output schema present, the description need not explain return values, and it adds reporting conventions on top. The only gap is not clarifying boundaries against balance-adjacent siblings such as billing_history, which an agent must resolve on its own.

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 takes zero parameters, so per the baseline this lands at 4. The description correctly does not invent parameter detail, and schema coverage is 100%.

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 opens with a specific verb and two concrete resources: the identity behind the configured API key and the account credit balance. It is clear what the tool returns, though it does not distinguish itself from siblings like billing_history or transactions that plausibly touch the same data.

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?

"Call this first when the user asks about their account, balance, or which key is in use" gives an explicit trigger condition and even a precedence rule. It stops short of naming alternatives (e.g., use billing_history for past charges), so the agent must infer when to switch.

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