get_balances

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

With no annotations, the description carries full responsibility. It discloses the absence of the `eth` field on Arc and warns against summing balances, plus states the error condition (no wallet). It does not explicitly state that the operation is read-only, but 'Reads' implies non-mutation. It is transparent but could explicitly mention read-only to be fully clear.

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 moderately sized but every sentence adds value. The core purpose is front-loaded, and the critical caveat about Arc is included without unnecessary elaboration. It could be slightly more compact, but the detail is justified given the network-specific behavior.

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 read tool with no output schema, the description provides essential behavioral context: what fields to expect, the special case for Arc, and the failure condition. An agent can predict the return shape and understand the cross-chain nuance without additional documentation. This is complete for its complexity.

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?

There are zero parameters and schema coverage is 100%, so the description has no burden to explain parameters. The baseline for no-param tools is 4, and the description correctly focuses on what the tool returns rather than input semantics.

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 identifies the tool as reading two balance types (USDC and gas token) for the active account on the active network, with specific chain names. It distinguishes itself from sibling tools by its focus on balances only, and the mention of the `eth` field and its absence on Arc adds precision.

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?

While it does not explicitly list alternatives or exclusion scenarios, it provides strong contextual cues (active account, active network, chain-specific behavior) that imply when to use it. The note about never adding USDC and gas on Arc is a critical usage guideline, but it does not state when to prefer other tools like get_history or get_wallet_status. Slightly short of perfect guidance.

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