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

Annotations cover the safety profile (readOnlyHint, destructiveHint false, openWorldHint), and the description layers on genuinely non-derivable behavior: deprecation status, USDC-only support, concrete rate limits (20 calls/min, ≥3s spacing), and field-level semantics (sourcePool null vs populated, isForSpending meaning, absence of trackingId). This is well beyond what the annotations provide.

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?

Front-loaded with the deprecated flag and purpose, followed by exclusion, applicability, field semantics, and rate limits — every sentence carries information an agent needs. It is dense to the point of being long, but no sentence is filler.

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?

With no output schema, the description compensates by explaining the shape and meaning of returned entries (sourcePool, isForSpending, missing trackingId) that an agent could not otherwise know. Deprecation, token scope, rate limits, and routing to alternatives are all covered.

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?

Only one parameter and schema description coverage is 100%, so the schema already documents walletAddress format and EIP-55 normalization. The description adds nothing parameter-specific, which is the correct baseline when the schema does the heavy lifting.

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?

States a specific verb+resource (get in-transit USDC bridge balances), scopes it ('funds moving cross-chain toward a destination pool'), and explicitly contrasts with the sibling get_balances for settled rebalancer balances. The deprecated tag and USDC-only constraint are stated up front, so an agent can select or avoid it immediately.

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?

Gives explicit when-not ('Does NOT include already-settled rebalancer balances — use get_balances for those') and names the alternative for tracking a single deposit ('use get_deposit_status with the trackingId from that call instead'). Token applicability limit (USDC only) is also spelled out, leaving nothing to inference.

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