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

Annotations already declare readOnly/idempotent/non-destructive/open-world, and the description still adds material context beyond them: a per-call price (0.003 USDC), p95 latency (1200 ms), the data source (Uniswap v3, USDC/WETH quotes), and an explicit coverage limitation (Aerodrome is not read). This is exactly the value-add expected on top of annotations.

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?

The core behavior is front-loaded in the first clause, then usage, exclusions, cost, and latency follow in compact sentences. No filler or redundancy.

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 spell out return values, yet it still hints at them ('with pool, fee tier and depth'). Cost, latency, source, and coverage limits are all disclosed, which is everything an agent needs to call this 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% and the single 'token' parameter is already documented with accepted forms (0x address or symbol examples). The description restates 'token on Base' but adds no syntax or format detail beyond the schema, so baseline 3 applies.

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 and resource ('Returns JSON with the USD price of a token on Base') plus the exact computation method (deepest Uniswap v3 pool against USDC or WETH). No sibling tool does anything similar, so it is trivially distinguishable from wallet-balances_v1 or sec-facts_v1.

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 ('crypto token price or market data for a Base token, quoted from on-chain liquidity') and explicit when-not ('token only trades off Base or on other DEXs (Aerodrome is not read), or you need history or OHLC'). Nothing is left to inference.

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