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

The annotations already mark it read-only and open-world, and the description adds important behavioral details: per-call pricing, free failed calls, quote behavior, and a free daily allowance. It also discloses what is returned even without an output schema.

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 front-loaded with purpose and return contents, followed by concise payment and usage notes. There is some repetition between the opening sentence and the final Returns line, but the structure remains efficient.

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 lookup tool with no output schema, the description is complete enough: it covers chains, hash formats, return fields, pricing, and payment flow. An agent has what it needs to decide whether and how to call it.

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 schema already documents the parameters well. The description still adds useful semantics by clarifying hash formats, chain defaults, and the critical constraint that the chain must match the hash.

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 states a specific verb and resource: look up a transaction on Base, Ethereum, or Solana. It also spells out the core outcome and return contents: success status, time, sender, fee, and token movements. This is clearly distinguishable from sibling tools such as wallet_balance or token_check.

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?

It explicitly says when to use the tool: when you have a transaction hash and need to know if it went through and what moved. It also explains the payment/quote flow, but does not name alternatives or explicit when-not conditions.

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