Child accounts with balances

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, covering the safety profile. The description adds useful context about the return contents (balance and bonusBalance in rubles) and scopes the data to children only, distinguishing it from get_balance. This goes beyond what annotations provide.

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 compact and front-loaded, with three sentences each serving a clear purpose: define output, state usage, and clarify scope. There is no wasted wording.

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?

Given the simple nature of the tool, strong annotations, and empty input schema, the description covers all necessary aspects: purpose, output format, scope, and alternatives. It is complete for an agent to use effectively.

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 no parameters, and schema coverage is 100%. With zero parameters, the description doesn't need to explain parameters, and a baseline of 4 is appropriate. The description could have mentioned that no parameters are required, but it's not necessary given the empty schema.

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 explicitly states it is the same list as list_child_accounts but includes each child's balance, clearly differentiating it from the sibling tool. It also specifies the resource (child accounts with balances) and the verb (list), making the purpose unambiguous.

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?

It gives explicit use cases: to see which child is out of money before transfer_funds/transfer_bonus, and to verify a transfer landed. It also notes that the parent's balance comes from get_balance, providing an alternative and clarifying when not to use this tool.

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