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

Annotations already cover read-only/open-world/non-idempotent, so the bar is lower, yet the description adds real context: cache staleness (up to 5 minutes old), supported chains, the exact output components, and the pricing model ($0.01 USDC via x402 or prepaid credits, free trial). The cost and staleness disclosures are exactly the behavioral facts an agent needs before calling.

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 purpose and the cached-tier qualifier, followed by output contents, coverage, and price. Every clause carries information an agent needs, and there is no filler or repetition of the schema.

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 no explanation, and the description still summarizes the verdict shape and its inputs. Chain coverage, cache age, and pricing are all stated. The only gap is not routing the agent to the live/deep siblings for fresher or deeper checks.

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 baseline is 3, but the description adds purpose-level meaning: amountUsd drives 'estimated price impact for your trade size' and fee share, side determines buy/sell framing, and chain feeds 'the chain's swap fee now'. This connects the parameters to the outputs rather than just restating the enum lists.

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 and resource ('pre-trade check before buying or selling a token') and names the tier ('cached, up to 5 minutes old'), which implicitly separates it from trade-precheck and trade-precheck-deep. It also enumerates the verdict output (go/caution/no-go) and the evidence behind it, so an agent knows what it gets. It stops short of naming a sibling to distinguish against, but the tier and price qualifiers do most of that work.

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?

The opening phrase gives the trigger context ('before buying or selling a token'), and the cache staleness hints at when this is appropriate versus a live check. However, there is no explicit when-not or named alternative (trade-precheck / trade-precheck-deep), leaving the agent to infer that freshness-sensitive trades should use a sibling.

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