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

Annotations already cover read-only/idempotent/non-destructive, but the description adds substantial undisclosed-by-annotation behavior: per-call x402 pricing ($0.002 USDC), that errors are free, 1-hour metadata caching, live reads from public Base RPC, invalid input returning 400 without charge, and a spoofed-symbol guard. This is exactly the behavioral context an agent needs before invoking.

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 pricing/scoping note is front-loaded and each clause carries information (proxy standards, bytes32 symbols, caching, error handling). It is dense and long for a single paragraph, but essentially every sentence earns its place, leaving only minor trimming opportunity.

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 no output schema, the description must convey return values, and it does so thoroughly (contract-vs-EOA, bytecode size, metadata, proxy impl, well-known flag, balance). Payment, caching, defaults, and error semantics are all covered, leaving nothing an agent needs 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?

Schema coverage is 100%, so the schema already documents both params and their defaults. The description reiterates that all params are optional and default to USDC, which is helpful but largely redundant with the schema; it adds little new per-parameter meaning beyond what is already structured. 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 specific verb (Inspect) and resource (token or any address on Base mainnet), then enumerates exactly what is returned: contract vs EOA, bytecode size, ERC-20 metadata, proxy implementation, well-known-token status, and optional holder balance. This is precise enough to distinguish it from siblings like base_wallet_balances and base_tx_status.

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?

Gives clear context for when to reach for it (inspecting any Base address, contract or EOA, defaulting to USDC) and notes the pricing/error conditions that govern use. It stops short of explicitly naming alternatives or stating when NOT to use it, so it falls short of a 5.

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