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

Annotations already cover read-only and non-destructive behavior. The description adds meaningful context beyond annotations: pricing, billing mechanism, free-tier allowance, lack of wallet/API key requirements, and the categories of output (action, risk read, notes). No contradiction with annotations.

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 well-structured and front-loaded with the core purpose. It includes billing and access details that are operationally relevant, and each sentence adds useful information without excessive fluff or repetition.

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 single-parameter tool with an output schema and read-only annotations, the description covers the essential invocation details: required input, network context, output contents, pricing/auth behavior, and access requirements. The agent has enough information to call and interpret the tool 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 description coverage is 100% and the sole parameter 'hash' is documented in the schema. The description adds mild value by specifying it must be a Base transaction hash and that it is required, but it does not deeply expand on format or validation rules beyond the schema.

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 verb ('explains') and resource ('any Base transaction'), and specifies the output type ('plain-English explanation'). It distinguishes itself from raw-decoding siblings like tx_decode by emphasizing that it turns raw calldata into an answer with risk reads and notes.

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 use case is clear: give a Base transaction hash and receive an explanation of what it actually did. It states the required input and describes what the output covers, but it does not explicitly contrast itself with sibling tools or state when not to use it.

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