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

Annotations already declare read-only, idempotent, open-world, non-destructive behavior, so the bar is lower. The description still adds meaningful operational context beyond them: pricing model ($0.02/call over x402 on Base), the prepaid x-credit-token option, no free tier, no API key required, and the data-source/coverage constraints.

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-loads the core purpose, but the opening redundantly restates itself ('Live floor price for a Base NFT collection — Current floor price for a Base NFT collection'), and 'For agents tracking NFT markets' and 'Required input: contract' add little. Information is dense but not tightly edited.

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, return-value details are not required, and the description covers pricing, payment mechanics, data sources, and coverage limits. Minor gaps remain around failure modes (e.g., unlisted collections) but nothing essential for correct invocation is missing.

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?

Single required parameter with 100% schema description coverage, so the schema carries the load. The description ('Pass the collection contract address') merely restates the schema without adding format details such as checksum expectations or chain qualifier beyond 'Base'.

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: retrieves the live/current floor price for a Base NFT collection, naming the data sources (OpenSea/LooksRare via Alchemy). No sibling tool provides NFT floor pricing (wallet_nfts lists holdings, not floor), so it is clearly distinguishable.

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 via 'For agents tracking NFT markets' and the coverage caveat ('limited to marketplace-listed collections'). There is no explicit when-to-use vs alternative guidance, though the absence of a direct sibling alternative softens the gap.

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