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

Annotations only declare readOnlyHint and openWorldHint; the description adds substantial non-obvious behavior: cost ($0.002 USDC per successful call), the payment rails (x402 on Base/Solana/Arc), and crucially that failed calls are not charged. This is exactly the kind of cost/auth context annotations cannot convey.

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-loaded with the core capability and dense with concrete detail; every sentence carries information. The pricing/payment sentence is placed last rather than surfaced earlier, and the paragraph is long, but there is little true 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?

An output schema exists so return values need not be re-explained, and annotations cover the safety profile. The description still adds coverage scope, chain support, price/liquidity enrichment, list membership, and the payment model, leaving nothing an agent needs to invoke it correctly unstated.

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% for both parameters, so the schema already documents chain and address fully. The description adds no syntax, format, or edge-case meaning beyond what the schema provides (e.g., no guidance on proxy vs implementation address handling), so the 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?

The description states a precise verb+resource and enumerates the exact fields returned (name, symbol, decimals, supply, EIP-1967 implementation for EVM; decimals, supply, authorities for SPL), plus scope across 22 EVM chains and Solana. This is highly specific, but it never names or contrasts with close siblings like evm_token, solana_token, or token_search, so sibling differentiation is left implicit.

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 strongly implied by the detailed coverage statement (you call it when you need on-chain token facts plus price/liquidity), but there is no explicit when-to-use, when-not-to-use, or alternative routing versus evm_token/solana_token/token_search. The only caveat offered is a disclaimer ('Information only, not financial advice'), which is not selection guidance.

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