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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety and external-lookup profile is covered. The description adds useful behavioral context beyond annotations by disclosing the $0.005 USDC per-call x402 payment and the payment endpoint URL.

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 two sentences and front-loads the core action before appending payment details. There is no wasted text, and every sentence contributes to understanding the tool.

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 simple read-only lookup with a fully described schema and no output schema, the description is complete enough. It states the chain, the lookup input, the returned fields, and the payment model.

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 the schema already documents both the required hash and optional payment parameter. The description mentions the hash lookup and pricing, but it does not add syntax or format details beyond what the schema provides.

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: looking up a Base transaction hash. It also enumerates the exact status and detail fields returned, which clearly differentiates it from chain-specific siblings like solana_transaction and from tx_explain.

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 description implies usage by saying it looks up a Base transaction hash, which gives enough context to know it is for Base chain transactions. However, it does not explicitly say when to use this instead of tx_explain or solana_transaction, nor does it state exclusions.

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