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

Adds substantial context beyond the annotations: 400 on malformed address, 404 on address without code, both uncharged, plus pricing ($0.01/call, first 25 free, failed calls free) and the explicit statement that repeats are charged because idempotentHint=false. This is exactly the kind of cost and failure-mode disclosure annotations cannot express.

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-loads purpose and the standards read, then attaches usage, error codes, example, and pricing in a tight sequence with every sentence carrying information. It is dense and the pricing clause is somewhat bolted on, but nothing is redundant.

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 covers what an agent needs: the input format by example, success semantics ('names the kind found'), and failure codes. It stops short of describing the exact response fields (e.g., whether the implementation address is returned per slot), which would fully close the loop.

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% for the single 'address' parameter, so the baseline is 3; the concrete example address adds a small amount of format confirmation. It does not add new constraints (e.g., checksum vs lowercase handling) 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?

States a specific verb and resource ('Find the implementation behind a proxy contract on Unichain') and even enumerates the resolution paths it reads (EIP-1967, beacon, admin, UUPS, OZ layout, EIP-1167). The chain prefix plus 'proxy' cleanly separates it from the many sibling *_proxy tools and from unichain_is_contract/unichain_storage.

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 when-to-use condition ('before trusting or decoding a contract whose code can be swapped by its admin') and routes to an alternative for a fuller verdict ('contract_risk'). The only weak point is that contract_risk is not among the listed siblings, so the agent cannot verify that pointer from the toolset alone.

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