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

Consistent with readOnlyHint=true ('nothing is signed or sent'), and adds substantial behavior beyond annotations: per-fee breakdown (0.5% Fivebar, router fee, gas), slippage-adjusted minimum, USD valuation, token-tax flagging, and missing-balance/approval detection when taker is supplied. This is rich disclosure the structured fields do not carry.

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?

Purpose is front-loaded in the first clause, with chain/DEX enumeration and fee details following. It is dense but every clause carries operational information; the long chain and DEX lists cost some readability, keeping it just under top marks.

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 fully describes what the agent gets back (amount out, minimum after slippage, USD value, itemized fees, tax and balance flags). For a read-only quote tool with 100% schema coverage, an agent has everything needed to call it and interpret results.

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 100%, so baseline is 3, but the description adds real meaning: chain is auto-selected for Solana tokens, and passing taker triggers balance/approval checks rather than being a passive field. Amount whole-unit semantics and slippage default are already in the schema, so it doesn't rise to 5.

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?

Opens with a specific verb+resource ('what swapping one token for another would give right now') and enumerates the chains, routing sources, and outputs. It clearly separates itself from swap_build (execution) and stock_quote (xStocks), so an agent can select it 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?

Explicitly states the when-not ('Quote only: nothing is signed or sent; to swap, use swap_build') and routes xStocks to stock_quote. It also implicitly scopes usage by chain and by passing taker for balance/approval checks, leaving nothing to inference.

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