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

With no annotations, the description carries the full burden and does well: it states data is read live from public RPC (read-only, no state change), discloses cost ($0.002 USDC per call via x402), and shows a sample response so return shape is predictable. It omits rate limits and what happens on failure/non-contract input beyond the is_contract flag.

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 purpose and supported capabilities, then usage, then pricing, then an example — a sensible priority order with little filler. The example output is truncated mid-object ("type":"zeppelin" with no closing braces), which undercuts an otherwise dense, efficient description.

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?

No output schema exists, and the description compensates by enumerating every field returned and including a sample payload, which is the right call for a no-output-schema tool. Combined with the pricing and RPC-source disclosure, an agent has enough to call it correctly; only failure modes and rate limits are absent.

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 coverage is 100% and both parameters are documented there, including the chain enum and default. The description restates the supported chains and shows an address in the example, but adds no syntax, casing, or address-validation guidance beyond the schema.

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?

Opens with a precise verb+resource ('Token contract inspector') and enumerates exactly what is resolved: contract check, ERC standard detection, metadata, supply, owner, and EIP-1967/beacon/1167/zeppelinos proxy detection. An agent can tell this is a read-only token introspection tool without opening the schema. It never names the closest sibling (token_preflight), so full sibling differentiation is missing.

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?

'Use before quoting, swapping, listing or paying with a token' gives a concrete trigger context for invocation. However, it offers no exclusions and does not point to the obvious alternative, token_preflight, which likely overlaps heavily — an agent choosing between the two gets no routing signal.

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