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

Annotations only declare readOnlyHint and openWorldHint; the description goes well beyond them with pricing ($0.002 USDC per call), failure-cost behavior ('failed calls cost nothing'), the free daily quota, and the no-wallet requirement for free calls. This is exactly the kind of cost/auth/retry context an agent needs before invoking a paid tool.

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-loads what the tool does and what it returns, then relegates billing mechanics to a compact second paragraph. Every sentence carries distinct information; nothing is redundant.

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 output schema, the description compensates by enumerating the returned fields, including the Solana-specific balance-change semantics. Payment prerequisites, pricing, and the quote handshake are all covered, so an agent has everything needed to call correctly.

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 hash format, chain enum, and payment payload are already fully documented in the schema. The description's explanation of the payment/quote loop restates the schema's own payment description rather than adding format or edge-case detail. 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?

Specific verb+resource ('look up a transaction') with scope narrowed to three named chains and an enumeration of exactly what comes back (success status, timestamp, sender, fee, token movements with symbols/amounts). An agent can immediately tell this is a transaction-verification tool, distinct from siblings like token_info or wallet_portfolio.

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 a concrete use case ('confirm a payment actually landed') and a clear payment workflow (omit `payment` for a quote, sign, call again). It stops short of naming or excluding alternatives among the many sibling lookup tools, so the routing guidance is contextual rather than explicit.

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