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

Goes well beyond the readOnlyHint/openWorldHint annotations by disclosing the metered cost ($0.005 USDC per call via x402), the spam-filtering behavior, the OpenSea floor-price data source, and the shape of the returned grouping. Payment requirements and filtering exclusions are exactly the kind of behavioral context annotations cannot 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?

Three tightly packed sentences: scope first, then output composition, then exclusions and cost. Every sentence carries new information and nothing is repeated from the schema or annotations.

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 usefully compensates by describing the grouped-by-collection return, sample item/image, and floor valuation. It omits any mention of result limits, pagination, or how large wallets are handled, which is the only notable gap for a holdings-listing tool.

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% (chain enum list and 0x address), so the schema already documents both parameters. The description restates the chain names and default but adds no syntax, format, or constraint detail beyond what the schema provides, 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?

States a specific verb+resource ('NFT holdings for any wallet') and enumerates the five supported EVM chains, which cleanly separates it from solana_nfts. It does not, however, explicitly distinguish itself from nearby siblings such as nft, nft_floor, or wallet_portfolio, leaving that inference to the agent.

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 only implied by the scope statement ('for any wallet on Base, Ethereum, Arbitrum, Optimism or Polygon'); there is no explicit when-to-use or when-not-to-use guidance. It never says to prefer solana_nfts for Solana wallets or nft_floor for a single collection's floor, so routing between siblings 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.