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

With no annotations provided, the description carries the full burden. It explicitly states 'Read live from the chain' (indicating real-time data and read-only behavior) and discloses a rate limit ('Free, 200 calls a day'). These are important behavioral details not inferable from the name or schema. It also says 'Everything public', clarifying it does not return private data. This goes beyond a simple 'get info' and provides useful operational context.

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 front-loaded with the core value proposition ('Everything public about one Arc address in one call') and follows with a concise list of what is included. Every sentence provides information: the data types, the live read behavior, and the rate limit. There is no wasted wording or redundancy. It is visually structured with a colon and list, making it easy for an agent to parse.

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?

The description is comprehensive for a single-parameter tool with no output schema. It enumerates the types of data returned (USDC/EURC/APEX balances, contract status, ERC-8004 identities, x402 selling), which gives an agent a clear picture of the output's scope. It also mentions live-read and rate limits, rounding out the operational context. It doesn't specify the exact return structure, but since there is no output schema and the data types are listed, this is sufficient for an agent to infer the shape. One minor gap is that it doesn't mention whether the tool returns zero values or handles errors, but this is not critical for a read-only overview.

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 fully describes the single parameter 'address' as '0x address on Arc', so schema coverage is 100%. The description adds no new meaning beyond the schema—it merely refers to 'one Arc address' without providing additional format, validation, or example. Since the schema already covers the parameter semantics, a baseline score of 3 is appropriate.

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 clearly states a specific verb ('get') with a resource ('everything public about one Arc address') and enumerates the specific data returned (USDC, EURC, APEX balances, contract status, ERC-8004 agents, x402 selling). It distinguishes itself from sibling tools like arc_contract_check (which focuses solely on contract status) and arc_agent_status (agent-specific) because it is a comprehensive single-call overview. The phrase 'in one call' also sets it apart from tools that might require multiple lookups.

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?

The description implies usage as a one-stop-shop for address information ('Everything public about one Arc address in one call') but does not explicitly state when to prefer it over alternatives, nor does it mention when not to use it (e.g., if only contract status is needed, arc_contract_check might be more direct). There is no mention of alternative tools or exclusions, so usage guidance is implied rather than explicit.

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