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

Despite readOnly/openWorld annotations, the description adds critical behavior: it returns an unsigned transaction plus approval step, never holds funds, runs a sellability check on unknown tokens, and refuses honeypots unless force=1. It also discloses pricing via x402, the x-credit-token header for unlimited calls, and one free call/day.

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-loads the core swap purpose and output, then covers safety and payment in a single dense paragraph. Slight redundancy appears in 'Swap on Base at best price' followed by 'An executable swap on Base,' and the paragraph is long, but every clause carries relevant 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?

An output schema exists, so return values need not be explained, yet the description still covers transaction, approval, minimum out, route, fees, payment, and auth. The absence of explicit alternative-tool routing and the force parameter mismatch keep it from being fully complete.

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 coverage is 100%, so the schema already documents all five parameters and the description adds only marginal parameter detail: token naming by symbol or address and a required-input list. It references force=1, which is absent from the schema, while slippage is only defined in the schema, creating minor inconsistency.

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 (swap), resource (tokens on Base), routing provider (0x across Uniswap, Aerodrome, Balancer, Curve, etc.), and the key output (a ready-to-sign transaction). Clearly distinguishable from siblings like near_swap, swap_route, or base_swap_validity by naming the chain and non-custodial output.

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 useful context: required inputs (sell, buy, amount, taker), token naming via symbols or 0x address, honeypot refusal with a force=1 override, and payment models. However it does not explicitly name an alternative swap tool or state when another sibling should be preferred instead.

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