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

Annotations already declare readOnly, idempotent, non-destructive, open-world, so the safety profile is covered. The description adds genuinely new behavioral context: it restates that nothing is placed, warns the quote is a snapshot that goes stale, and advises re-quoting before acting.

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-loads the core action in the first sentence, then covers returns and the staleness caveat. The return enumeration is long but each item is informative; little waste overall.

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 no output schema, the description carries the return-value burden and does so thoroughly (total, average price, legs, single-market comparisons, savings line, warnings). Combined with annotations covering safety, an agent has enough to call it correctly; only explicit sibling routing guidance is missing.

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 80%, so the schema already documents qty, asset, split, and slippage_bps. The description adds the unit convention ('All amounts are QU; quantities are whole units') and implies split's effect, which is marginal added value on top of an already well-documented schema. Baseline 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?

States a specific verb (prices an order, finds the cheapest route) and a concrete resource (QX order book + QSwap pool), and distinguishes its scope from single-venue siblings by describing cross-venue routing and splitting. An agent can tell this is the multi-venue routing quote without opening any schema.

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?

Usage is implied rather than stated: 'Nothing is placed' and 're-quote before acting' suggest it is a pre-trade preview, but no sibling (e.g. qmax_swap_quote) is named as an alternative and no explicit when/when-not condition is given. Adequate but leaves routing choice to inference.

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