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

Annotations already cover readOnlyHint and openWorldHint, and the description adds genuinely new behavior: multi-source resolution (IPFS, Arweave, data URIs, https) and the concrete cost ($0.005 USDC via x402). It stops short of explaining the x402 payment/auth flow the agent must complete.

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, zero filler, with the core resource stated first and the cost constraint appended. Every clause earns its place.

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 still conveys what is returned (metadata), where it is resolved from, and the micro-payment model, which is roughly what an agent needs. The unresolved x402 payment mechanics are the main remaining gap for a paid, open-world read.

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 0%, so the description carries the burden for the two required parameters, yet it says nothing about contract vs tokenId beyond implying an ERC-721/1155 identity. The schema's regex patterns help validation but add no semantic meaning.

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 resource (NFT metadata for an ERC-721/1155 token) and chain (Base), which cleanly separates it from the sibling base_nft_owner even though no sibling is named. The verb is implied by the noun phrase rather than stated, keeping it just short of a 5.

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?

No when-to-use guidance, prerequisites, or alternative routing is provided. It never tells the agent to prefer base_nft_owner for ownership checks or when metadata lookup is the wrong call.

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