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

Annotations already declare readOnly, idempotent, openWorld, and non-destructive, so the safety profile is covered. The description adds genuinely useful non-annotation behavior: the x402 $0.04/call pricing on Base, the prepaid x-credit-token header for unlimited calls, a 1-free-call/day tier, and 'no API key required'. It does not contradict the annotations.

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 hook question is front-loaded and the operational facts (inputs, pricing) come later, which is reasonable. But the MEV-education copy ('easiest MEV prey', '~$50M/quarter tax', sandwich economics) is padding that does not help an agent select or invoke the tool.

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 not be spelled out, yet the description helpfully summarizes the output shape (exposure read + protected-execution plan). Required input, pricing, and auth are all covered. An agent has everything needed to call it correctly.

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%, so the schema already documents both parameters. The description repeats 'Pass tokenOut + amountUsd' and flags tokenOut as required but adds no format, unit, or syntax detail beyond what the schema provides. Baseline 3 is appropriate 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?

The description states a specific verb+resource: it returns an MEV/sandwich exposure read (low/elevated/high) plus a protected-execution plan for a swap. This is distinguishable from generic swap/route siblings and it points to the related validity-build tool. It is slightly bloated with marketing framing, but the actual purpose is clear.

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?

It implies the usage context (checking a swap for sandwich exposure and getting guidance to land it safely) and references a sibling (validity-build) as part of the plan. However, it never states explicit when-not conditions or how to choose between this and other pre-trade or swap tools, leaving routing partly to inference.

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