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

Annotations already declare destructiveHint=true, idempotentHint=false, and openWorldHint=true, so the agent understands this is an irreversible state-changing cross-chain operation. The description adds the useful cost context ($0.25 USDC), but says nothing about irreversibility, confirmation needs, or failure handling beyond what annotations supply.

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?

A single sentence that front-loads the action and resource, then tacks on mechanism, source, and cost. No filler; every clause earns its place.

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 an output schema present, return values need no explanation, and annotations cover the mutation/safety profile. The description supplies source chain and fee, which are the key contextual facts; only explicit usage guidance for choosing this over manual alternatives is missing.

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 description coverage is 100% and all three parameters are documented, including an enum for destinationChain, so the schema carries the burden. The description adds no parameter-level detail beyond what the schema already states, making 3 the correct baseline.

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 (Bridges), resource (USDC), source (Arc Mainnet), and mechanism (Circle CCTP), so the agent knows exactly what operation this performs. It does not differentiate from siblings, but no sibling tool offers cross-chain bridging, so the omission is minor.

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?

Usage is implied by the description: use it when USDC sits on Arc Mainnet and needs to reach another chain. There is no explicit when-to-use/when-not statement and no named alternative, since none of the siblings overlap, so this is only minimally adequate.

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