get_activity_balances

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

Without annotations, the description carries the full burden of disclosing behavior. It does state that only day-level aggregation is supported, which is a useful constraint. However, it omits other behavioral traits such as authorization requirements, rate limits, data freshness, or what happens when no data matches.

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 extremely concise at two sentences, with no extraneous information. Every word serves a purpose, and the most important information (cardholder-level, day aggregation, expandability) 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?

Given the tool has 6 parameters, no output schema, and no annotations, the description is insufficient for an agent to fully understand the tool. It does not explain the meaning of 'cardholder-level', the available fields, date filtering behavior, or how network expansion works, leaving significant gaps.

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?

Input schema coverage is 100%, so each parameter already has a description. The tool description adds only a mention that data is 'expandable by network', which aligns with the 'expand' parameter described in the schema. The description provides no additional semantic value beyond the 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 clearly states the tool retrieves cardholder-level balance data, specifies it includes individual balances and is expandable by network, and notes day-level aggregation only. This provides a specific verb and resource, and implicitly distinguishes from program-level balance tools like get_program_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?

No guidance is provided on when to use this tool versus siblings such as get_activity_balances_network_detail or get_program_balances. The description does not mention prerequisites, alternatives, or scenarios where this tool is preferred.

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