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

Adds substantial context beyond the annotations: error semantics (400 for malformed address, 404 for address without code, both uncharged), pricing ($0.01/call, first 25 free, failed calls free), and an explicit note that repeats are charged, which explains the non-obvious idempotentHint=false. It doesn't describe the response shape (what the 'kind' values are), but the safety/pricing profile is well covered.

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 the enumerated standards, then usage, errors, pricing. Most sentences earn their place, but the payment/free-tier clause is lengthy relative to the tool's core purpose and could be tightened.

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 tool with no output schema, the description covers purpose, alternatives, errors, and cost. The one gap is that the return value is only gestured at ('names the kind found') without indicating the possible kinds or fields, which matters since no output schema exists.

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% with a single 'address' parameter, so the baseline would be 3; the description earns an extra point by supplying a concrete example address that pins down the expected 0x format, and by describing address-level failure modes (400/404).

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 and resource ('Find the implementation behind a proxy contract on Linea') and enumerates exactly which storage slots and proxy standards are read (EIP-1967 impl/beacon/admin, EIP-1822 UUPS, OZ legacy layout, EIP-1167 bytecode). This clearly distinguishes it from sibling read tools like linea_storage or linea_is_contract, which don't resolve proxy targets.

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 an explicit trigger ('use before trusting or decoding a contract whose code can be swapped by its admin') and names the alternative for a different need ('for a fuller risk verdict use contract_risk'). Nothing about when to pick this versus a sibling is left to inference.

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