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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint. The description adds no behavioral context beyond the annotations, such as caching behavior, chain handling, or response shape. It provides no extra value for an agent.

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 description is extremely short, but for a tool with 4 parameters and a specific purpose, this is under-specification rather than deliberate conciseness. It omits critical information that would fit in a few more sentences.

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 a 4-parameter schema, sibling tools, and an output schema, the one-line description is insufficient. It does not address chain defaults, the meaning of refresh_cache, or how this differs from nfts_for_collection. The output schema covers return values, but usage and selection context 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?

The schema has 0% description coverage, so the example is the only hint for parameters like contract and tokenId. The description does not explain any parameter semantics, nor does it clarify optional parameters like chain or refresh_cache. An agent cannot understand what inputs to provide beyond the example.

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 'Single NFT metadata' clearly identifies the tool's scope as metadata for one NFT, which distinguishes it from siblings like nfts_for_collection or nfts_owned. However, it lacks an explicit verb like 'retrieve' or 'get', so it's not a fully specified purpose statement.

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?

There is no guidance on when to use this tool versus alternatives such as nft_owners, nfts_for_collection, or nfts_owned. The description does not mention use cases or exclusions, leaving the agent to guess.

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