账户余额

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

Annotations already cover read-only, idempotent, non-destructive behavior, lowering the burden. The description adds valuable return-shape detail: data is a direct amount string in yuan, and points out that the balance breakdown lives elsewhere. This goes beyond annotation coverage without contradicting it.

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?

Two short sentences, front-loaded with the core purpose, followed by the return format and the cross-reference to user_info. Every clause 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?

For a parameterless, annotation-covered read operation, the description is complete: it defines what is returned, the unit, the data shape, and where to find related breakdown information. No output schema exists, so the in-description return details are appropriately sufficient.

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?

There are zero parameters and the schema is already 100% covered, so the description has no parameter semantics to add. Baseline 4 applies because no parameter documentation is needed at all.

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 action and resource: '查询当前账号余额' (query current account balance). It also distinguishes itself from sibling user_info by pointing there for the recharge/gift balance split, so an agent can tell what this tool returns versus user_info.

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 clearly implies use when you need the current account balance and explicitly routes the agent to user_info when a recharge/gift split is needed. It lacks a broader when-not-to-use statement, but for a parameterless balance query the routing cue is strong.

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