list_balances

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

With annotations already indicating a safe read operation (readOnlyHint=true), the description adds useful behavioral context: it lists accounts, returns currency balances with available amounts, and explains the structural difference between STANDARD (one per currency) and SAVINGS (multiple jars). No contradictions with annotations.

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 sentences: first states the action and scope, second explains return value and types. No redundant wording, front-loaded with the most important information.

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 low parameter count (2), full schema coverage, and no output schema, the description reasonably covers the return format (currency balances with available amounts) and type semantics. Could mention pagination or error handling, but not critical for a simple list operation.

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?

Schema covers both parameters at 100%, so the baseline is 3. The description adds semantic meaning to the types parameter by clarifying that STANDARD is one per currency while SAVINGS includes multiple 'jars' per currency, which enhances understanding beyond the schema's basic enum-like description.

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 uses a specific verb ('List') and resource ('balance accounts for a profile'), clearly stating the scope. It distinguishes from sibling tools like get_balance by emphasizing 'all balance accounts' and explains the STANDARD vs. SAVINGS distinction.

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?

Provides clear context that this is for listing all balances for a given profile, with an optional types parameter to filter STANDARD or SAVINGS. Does not explicitly mention alternatives (e.g., when to use get_balance), but the scope is unambiguous.

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