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

Annotations already cover the read-only, non-destructive, open-world nature. The description adds behavioral context beyond that by explaining the result is resolved across all chains and that no chain argument is required. This is meaningful and consistent with the annotations.

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 sentences, all substantive: the core behavior, the intended use case, and the cross-chain parameter clarification. There is no filler, and the most important information is front-loaded.

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?

For a single-parameter, read-only lookup with an output schema and safety annotations, the description is complete. It covers what the tool returns, why to use it, and the key behavioral nuance about chain resolution. Nothing essential is missing for an agent to invoke it correctly.

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 must compensate for parameter meaning. It does clarify that the lookup target is an EVM wallet and explicitly says no chain argument is needed, which adds value. However, it does not explain the request wrapper structure or address format, leaving the generic 'request' parameter and its anyOf schema somewhat ambiguous.

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 opens with a specific verb and resource: 'Get the first address that ever funded an EVM wallet,' and also names the returned fields (transaction hash, chain, timestamp). This clearly distinguishes it from sibling address_* tools, especially with the explicit note that no chain argument is needed because resolution is cross-chain.

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?

It gives a concrete use case: attribute an unlabelled wallet to a known entity, since the first funder is often a CEX withdrawal or another wallet the same owner controls. It does not explicitly name alternatives or state when not to use it, but the context is clear enough to guide selection among the many sibling tools.

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