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

Annotations already declare readOnly, idempotent, non-destructive and openWorld, so the safety profile is fully covered elsewhere. The description adds no behavioral context beyond that — no error behavior for unknown hashes, no rate/latency notes — and the field list it does give duplicates the 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?

A single front-loaded sentence with no filler; the verb and resource lead and the field list follows. Slightly compressed to the point of omitting usage context, but nothing is wasted.

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?

With 100% schema coverage, an output schema, and annotations carrying the safety profile, the essentials are covered. However a decode tool with no note on invalid/missing hash handling or which chain defaults apply leaves small gaps an agent may need to discover at call time.

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% with only two parameters, both documented in the schema (chain default: base, txHash). The description adds nothing about parameter semantics, so the baseline 3 for high coverage applies.

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?

States a specific verb ('Decode') and resource ('a transaction') and enumerates the decoded fields, so the agent knows exactly what comes back. It does not differentiate itself from nearby read tools like chain.block or security.contract.events, but no sibling is a true duplicate.

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?

There is no statement of when to reach for this tool versus alternatives, and no prerequisites or input-format guidance. The agent must infer usage purely from the name and one-line purpose.

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