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

With readOnlyHint=true already present, the description adds valuable context: the x402 payment protocol, the 0.003 USDC cost on Base, and the explicit clarification that the tool does not pay. It does not fully describe the return format, but the key behavioral constraint is disclosed.

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 description is a single compact statement with the core purpose front-loaded and no wasted words. Parenthetical contents are dense but useful.

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?

For a zero-parameter, no-output-schema info tool, the description covers the snapshot contents, price, protocol, network, and non-payment behavior. It could more explicitly state that the tool returns purchase instructions, but it is otherwise complete.

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?

The tool has zero parameters, so parameter semantics are inherently simple and the schema needs no compensation. Baseline 4 is appropriate.

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 clearly states the tool explains how to buy a full token snapshot via x402 for a specific price on Base, and lists the snapshot contents. It does not explicitly differentiate from the sibling token_basics tool, which keeps it from a 5.

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?

Usage is implied: use this when you need instructions for purchasing the full snapshot. However, it never states when not to use it or explicitly compares it to token_basics, leaving the agent to infer the routing.

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