investments_balances

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It only states the output content, not whether the operation is read-only, the freshness of the data, or any error conditions. For a balance query, read-only behavior is implied but not explicit, and no other behavioral traits are disclosed.

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 a single, tightly-worded sentence that communicates the essential output without any waste. It is front-loaded with the core purpose and includes the total as a secondary element. Every word contributes to understanding.

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 simple, parameterless tool, the description is reasonably complete. It indicates the result is a per-account breakdown plus a total, which implies a structured response. However, it doesn't specify the return format (e.g., JSON object vs. array) or any nuances like sorting or currency, but those are minor gaps given the simplicity.

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 has zero parameters, so the schema is trivially covered. The baseline for 0 params is 4, and since the description doesn't need to explain parameters, there is no penalty. The description adds no parameter semantics because there are none to explain.

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 returns 'latest balance per investment account, plus the total.' It specifies the resource (investment balances) and the output (per-account and total), which distinguishes it from sibling tools like investments_transactions or investments_holdings. However, it doesn't explicitly differentiate itself from investments_summary, which might also return balances, so it falls short of a 5.

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 provides no guidance on when to use this tool versus alternatives. It doesn't mention any conditions that would favor this over investments_summary or holdings, nor does it state any prerequisites or typical use cases. Agents are left to infer usage from the name alone.

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