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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds real value beyond that: it says the tool is free, that every paid Privi tool accepts PRIVI, and that reserves indicate whether a swap can fill - operational context the annotations do not carry. It stops short of describing price freshness or where the data is sourced from.

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?

Two sentences, front-loaded with what the tool returns before the pricing note. The trailing 'Every paid Privi tool also accepts PRIVI. Free.' is mildly tangential but is a genuine cost signal rather than filler.

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 an output schema present, the description need not enumerate return fields, and it does cover the substantive cases (price, reserves, pools, quote) plus the free-tier behavior. The only modest gap is not clarifying how fresh the market data is or what happens when a quote is requested without sufficient liquidity.

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 the 'side' enum-like buy/sell semantics and 'amount' units are already documented in the schema. The description only signals that a quote is optional, adding no syntax or defaulting detail beyond the structured fields - baseline 3.

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 concrete resource set: PRIVI price on Base, swap-desk reserves of PRIVI/USDC, Uniswap v3 and Aerodrome pools, plus an optional swap quote. That is specific enough to distinguish it from most siblings, though it never names the neighbouring quote/payment tools (privi_test_payment_quote, privi_payment_options) it could be confused with.

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 by the content listed - check price, check whether the desk can fill a swap, get a quote. There is no explicit when-to-use or when-not clause and no direction to the sibling quote or payment tools, so the agent must infer routing itself.

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