Find the best swap output across Base aggregators by providing sell token, buy token, and amount. Set optional slippage for precise quotes.
Best swap output across Base aggregators (quote only, no calldata). Costs $0.005 USDC via x402.
| Name | Required | Description | Default |
|---|---|---|---|
| buy | Yes | Token address or ETH | |
| sell | Yes | Token address or ETH | |
| amount | Yes | Sell amount in the sell token's smallest unit, as a decimal string | |
| slippageBps | No | 1..5000, default 50 |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden. It discloses the $0.005 USDC cost via x402 and that it returns a quote only, no calldata. However, it doesn't describe response contents, failure modes, or whether a swap is ever executed, leaving some behavioral ambiguity.
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, front-loaded sentence with zero waste. It communicates the core purpose, scope, and cost efficiently.
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?
There is no output schema, yet the description doesn't specify what the returned quote contains (e.g., output amount, route, aggregator). It does mention the fee and quote-only nature, but for a paid tool, more contextual detail about return format would make it more 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 input schema already fully documents each parameter. The description adds no parameter-specific meaning beyond the schema, so the baseline score of 3 is appropriate.
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 states that the tool finds the best swap output across Base aggregators and explicitly says it's 'quote only, no calldata.' This distinguishes it from swap_route in function, though it doesn't name the sibling directly.
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?
No explicit guidance on when to use this tool versus alternatives like swap_route. The phrase 'no calldata' implies a quote-only use case, but there is no direct when-to-use/when-not-to-use or mention of sibling tools.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.