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

Annotations already cover read-only, idempotent, non-destructive semantics, and the description adds value on top: it discloses that no transaction is built, that the quote is already fee-adjusted, the 409 behavior, and that an API key from trnch_register must be sent as a Bearer token. That is behavior an agent cannot infer from the structured fields.

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?

Three tight sentences, front-loaded with the core action and return value, then usage routing, then error/auth constraints. No filler or repetition of the title or 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?

No output schema exists, but the description still explains what comes back (best amount out, fee-adjusted, plus router). Auth requirements and the 409 failure mode cover the remaining operational gaps for a read-only quote call.

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 tokenIn, amountIn, slippage, and decimals are already fully documented, and the description adds no per-parameter detail beyond what the schema states. Baseline 3 applies when the schema carries the semantic load.

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?

Specific verb plus resource ('Quote any pair across six routers'), with the returned value spelled out: best amount out net of the TRNCH fee plus the router. It is clearly distinguished from siblings by naming trnch_buy and trnch_sell as the trading alternatives.

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?

Explicit when-to-use ('Use it to compare before buying') and when-not-to-use, routing the agent to trnch_buy/trnch_sell for actual trades. It also names a concrete failure condition (409 for non-tradable tokens) and the auth prerequisite.

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