Is this the real token?

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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the bar is lower. The description still adds real value: 'Instant, no ledger call' discloses the lookup is against a hardcoded issuer list rather than a live ledger query, which explains latency and 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?

Opens with the question it answers, then gives the issuer list and the two usage modes. The inline addresses make the sentence dense, but they are load-bearing reference data and the overall text is front-loaded with 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?

An output schema exists, so return values need not be described, and both call modes are covered. The one omission is scope: it does not say the verified list is limited to RLUSD/USDC/SOLO, so an agent could wrongly assume it validates arbitrary tokens.

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 a 3 is the baseline, but the description goes beyond the schema by explaining the interaction between the two parameters: omitting issuer yields the official issuer, while supplying it turns the call into a confirmation/imitation check. That is semantic meaning the schema's 'Optional issuer address to verify' does not convey.

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 question it answers ('is this the real RLUSD / USDC / SOLO?') and names the verification basis (verified official issuers). This is clearly distinct from the siblings check_token_safety and check_wallet_security, which address safety/security rather than issuer authenticity.

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 explicit invocation modes: 'Give the ticker alone to learn the official issuer, or ticker + issuer to confirm or expose an imitation.' That is clear when-and-how guidance for the two call shapes, though it never states when to prefer a sibling tool over this one.

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