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

Annotations already declare readOnlyHint=true and openWorldHint=true, and the description reinforces this ('Quotes only; ISHOB never sends transactions'), which is consistent rather than contradictory. It adds substantial context beyond the annotations: the aggregator source and liquidity breadth, the exact output fields (output amount, slippage-protected minimum, USD value change, gas, hops), the conditional unsigned-transaction behavior, and the payment model ($0.001, x402).

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 core purpose in the first sentence, followed by the output list, the conditional `sender` behavior, the read-only boundary, and pricing. It is dense but every clause carries information; the parenthetical detail is slightly heavy, keeping it from a 5.

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, so the description compensates by enumerating the returned fields (output amount, slippage-protected minimum, USD value change, gas, hops). The conditional `sender` behavior, the read-only guarantee, and the payment requirement are all disclosed, leaving no material gap for an agent to call this tool 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 baseline is 3. The description adds real meaning on top of the schema by explaining the effect of `sender` (unsigned ready-to-sign transaction plus allowance check) and by surfacing slippage protection as a returned quantity tied to slippage_bps, letting the agent understand parameter consequences without inferring them.

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+resource (best DEX swap route and quote) and names the underlying mechanism (KyberSwap aggregator, 400+ liquidity sources, split routes) across six named chains. This is clearly distinguishable from siblings like simulate_tx, token_audit, or wallet_portfolio because it is explicitly a quote/route tool.

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?

Gives clear conditional usage: 'With `sender`, also an unsigned ready-to-sign transaction plus the ERC-20 allowance check.' The line 'Quotes only; ISHOB never sends transactions' tells the agent this is a read/quote path, not execution. It does not explicitly name an alternative (e.g. simulate_tx) for pre-execution simulation, so it stops just short of full when/when-not guidance.

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