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

Even though annotations cover the safety profile (readOnly, idempotent, non-destructive, openWorld), the description adds substantial behavior an agent cannot infer: cost of $0.009 USDC via x402, that unpaid calls return 402 even on bad queries, that signed calls with invalid args are rejected before settlement and not charged, and that results may be cached/stale with cacheAgeMs. It also discloses the important domain rule that labeled exchange hot wallets are not clustered, which directly affects result 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?

Well front-loaded — the trigger and core action lead, with billing and caching semantics trailing. It is slightly long with some redundancy: sentence two restates the funder-finding action from sentence one, and the HTTP GET price parity detail is marginal for MCP selection.

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?

Complete for a 2-parameter tool with no output schema: the description explains what is returned (cluster id, plain-language sybil risk reasons, cached/stale/cacheAgeMs) and covers the payment failure modes an agent must anticipate. Nothing needed to call it correctly is missing.

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%, so baseline is 3. The description mentions 'Optional peers compares up to 8 other wallets', but the schema already documents the comma-separated up-to-8 peers constraint and the base58 address format, so the description adds essentially nothing beyond the structured fields.

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+resource: find a wallet's first SOL funder, flag wallets sharing that funder or a CEX deposit address, return a cluster id with sybil risk reasons. This is clearly distinct in kind from siblings like wallet_preview or token_trending, though it never names them explicitly, so sibling differentiation is implied rather than stated.

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?

The opening 'Use this when you need a wallet's first SOL funder and whether other wallets look like the same operator' gives an explicit trigger condition, and it explains the optional peers comparison. It stops short of stating when-not-to-use or naming which sibling to pick instead.

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