subaccount_get_balance_summary

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

With no annotations, the description carries the full burden of behavioral disclosure. 'Get' and 'Returns' signal a read-only retrieval, and it states the scope ('all subaccount balances and charges'), but it does not describe aggregation behavior, permission requirements, or whether the data is real-time. No contradiction with annotations exists.

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 short and front-loaded, which is appropriate for a zero-parameter tool. However, the 'Returns: Summary of subaccount financial status' line merely restates the first sentence and adds no new information, so not every line 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 zero-parameter retrieval tool, this description is sufficient: the output schema covers return details, and the resource scope is stated. The absence of usage guidance and broader subaccount context keeps it from being fully complete, but an agent can safely invoke this tool with what is provided.

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 input schema is empty, so the schema already conveys that no arguments are needed. The description adds useful scope by saying the summary covers 'all' subaccounts, which explains why no parameterization is required.

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 states a specific action ('Get') and a distinct resource ('summary of all subaccount balances and charges'), which differentiates it from sibling tools like subaccount_get_status_overview and subaccount_analyze_costs. It is clear, though it does not explicitly name siblings and leaves mild scope ambiguity in 'all subaccount balances.'

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 intended use is implied: call this when you need an overall subaccount financial summary. However, it gives no explicit when-to-use guidance, no exclusions, and no pointers to alternatives such as subaccount_monitor_usage or subaccount_analyze_costs.

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