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

Annotations already cover read-only, idempotent and open-world behavior. The description adds useful context beyond them: price tier (free vs paid sibling) and the deliberate absence of risk scoring. It stops short of saying what is returned when an address is not a contract or not an ERC-20, which would matter for interpretation.

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?

Three short sentences, front-loaded with the 'Free' qualifier and the core purpose, then the returned fields, then the sibling routing. No filler.

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 does list the meaningful return fields and the routing alternative, which is the main thing an agent needs. It is slightly incomplete in not describing the response for non-ERC-20 or EOA addresses (e.g., whether fields are null or omitted).

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 description coverage is 100%: the single address parameter is fully documented including the 0x pattern and Base mainnet chain. The description only repeats the chain context and adds no syntax or semantic detail beyond the schema, so the 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 check (contract vs ERC-20 on Base mainnet) and the exact metadata returned (name, symbol, decimals, total supply). It distinguishes itself cleanly from check_base_token by explicitly excluding risk analysis.

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?

Explicitly frames itself as the free metadata path and names the paid alternative check_base_token with the condition that selects it (SAFE/CAUTION/DANGER verdict). The exclusion ('No risk analysis') removes ambiguity about which sibling to call.

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