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

With no annotations, the description carries the full burden and does disclose key traits: the data is read live from the chain (freshness), the call is free with a 200/day rate limit, and the returned balances are enumerated including USDC's 18-decimal native convention. It omits failure behavior for malformed or empty addresses, which is the main residual gap.

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-loaded with the value proposition ('Everything public about ... in one call'), followed by a compact enumeration, then freshness and cost constraints. Every clause carries information; nothing is redundant filler.

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 composite tool with no output schema, the description appropriately enumerates what comes back, which is the critical missing structure. It stops short of describing the response shape or how partial/empty results are represented, but it is otherwise sufficient to call the tool 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?

There is a single required parameter with 100% schema description coverage ('0x address on Arc'), so the schema already does the work. The description adds no extra semantics about the address (e.g., accepted formats, whether it can be an EOA or contract, whether checksum matters), so 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 concrete verb-equivalent (read everything public about one Arc address) and enumerates the exact resources returned: USDC/EURC/APEX balances, contract status, ERC-8004 identities, and x402 seller status. The 'in one call' framing distinguishes this omnibus lookup from narrower siblings such as arc_wallet_value and arc_contract_check.

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 implied rather than stated: 'one call' suggests it is the consolidated first-pass lookup, and 'Free, 200 calls a day' gives a practical budget constraint. However, no sibling alternative is named and there is no guidance on when to prefer the narrower tools or what to do when the address has no activity.

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