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

No annotations exist, so the description carries the full burden and does well: free, deterministic, no external calls, 60 calls/min per client, and an explicit negative scope ('says nothing about who controls an address'). It omits error behavior for malformed chains, which keeps it short of a 5.

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 as a question that states the core purpose immediately, then cost/scope/rate-limit details. The mid-sentence parenthetical listing outputs is slightly dense but every clause carries information.

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 annotations and no output schema, the description must supply everything, and it does cover inputs, per-chain behavior, outputs, cost, rate limit, and scope limits. It stops short of describing return shape or failure modes, which is the only remaining gap for a stateless check.

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 baseline is 3, and the description adds real semantics beyond it: the chain parameter selects the validation regime (EIP-55 vs base58/32 bytes), and it enumerates the outputs tied to the address input (valid, checksummed form, checksum correctness, casing).

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 precise verb+resource framing ('is this address well formed for this chain, and what is its EIP-55 checksummed form?') and names the two supported families (EVM EIP-55, Solana base58). It is trivially distinguishable from every sibling tool, none of which touch address validation.

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 (free, deterministic, no external calls) and an explicit scope boundary: 'Format only; says nothing about who controls an address.' That tells the agent when NOT to rely on it. No alternative tool is named, but no sibling overlaps functionally, so there is nothing to route against.

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