decode_calldata_or_failed_tx

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

Annotations already declare the read-only, idempotent, non-destructive, and open-world profile. The description adds useful behavioral context beyond that: it replays reverted transactions at the exact block, decodes 4-byte signatures and parameters, and flags malicious approvals. It still omits error handling and rate-limit behavior, but the added context is substantial.

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 definition is a single front-loaded sentence with the most important context ('ZERO API KEY REQUIRED') first and no extraneous content. It is dense and slightly run-on, but every clause contributes to understanding what the tool does.

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?

Given the absence of an output schema, the description adequately signals what comes back: decoded 4-byte signatures and parameters plus malicious-approval flags. Combined with annotations covering the safety profile, an agent has enough to call the tool correctly, though return-error behavior and exact response shape remain unspecified.

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 parameters, including the 'base'/'eth' enum for chain. The description restates the input forms (hex calldata or 66-char tx hash) but adds no new syntax, format, or constraint 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: it decodes raw calldata, custom revert errors, and failed transactions, and it explicitly lists what it can accept (hex calldata or a 66-char tx hash). It does not, however, differentiate itself from nearby tools such as simulate_transaction_preflight or inspect_contract_abi_and_proxy, so sibling routing is left implicit.

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 when the tool is applicable by describing the accepted inputs and the post-mortem replay capability. It does not state when to prefer this over simulate_transaction_preflight or another sibling, nor does it mention exclusions or prerequisites beyond 'zero API key required'.

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