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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so safety is covered structurally. The description adds what annotations cannot: it is free, keyless, and requires no signer, which is genuinely useful pre-call context. It does not describe caching, staleness of addresses, or registry failure modes.

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?

The critical instruction and the disambiguation warning are front-loaded well, but the tail is redundant: "Free, keyless, read-only. Cost and signer: free and keyless, nothing to sign." repeats the same two facts across back-to-back sentences, wasting a full sentence of a five-sentence description.

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 one optional parameter, an output schema to cover return values, and rich annotations, the description supplies everything an agent needs: what it returns (canonical addresses), when to call it, auth/cost profile, and a concrete confusion hazard to avoid.

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% for the single optional `symbol` parameter, including an example, so the schema carries the load. The description adds no formatting or semantics beyond what the schema states. 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?

The description names a specific resource (the canonical on-chain address for every token operated) and its authoritative source ("the registry the rails themselves use"). The ECOWEALTH vs EWP warning sharpens what the tool is for. It stops short of naming the nearest siblings (crypto_wallets, regen_address_lookup), so the agent must infer the boundary.

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?

"Ask this BEFORE using any token address" is an explicit, imperative usage rule with a clear trigger condition. No exclusion cases or named alternatives are given, but the positive guidance is unambiguous.

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