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

With no annotations present, the description carries the load well: it discloses that validation is local, that an RPC call happens only when check_code is set, and names the price ($0.001 via x402). It does not spell out failure behavior (malformed input, unsupported chain) or the full response shape.

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?

Four short sentences, front-loaded with what the tool does, then cost and RPC behavior. No filler; each sentence contributes a distinct fact.

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?

There is no output schema, so the description must convey return values, and it only partially does — the eoa|contract label is mentioned but the overall result (validity flag, normalized address, detected chain) is not. Pricing and RPC behavior are covered, so it is adequate but not complete.

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 75%, and the description adds real meaning on top: it maps chain values to the specific validation algorithms used and explains that check_code triggers eth_getCode on Base to yield eoa|contract. The 'auto' value and the request_id idempotency behavior are left to 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 (validate an address) plus the exact chains and algorithm families covered (EIP-55 checksum, base58, bech32). An agent can distinguish this from siblings like token_risk or erc20_meta without opening the schema.

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?

Offers real context for invocation — local validation by default, no RPC needed, optional eth_getCode on Base — but never says when to prefer this tool over a sibling (e.g. token_risk) or when chain=auto should be chosen versus an explicit enum. Usage is implied rather than stated.

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