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

Beyond the annotations (which already declare readOnly/idempotent/non-destructive), it discloses the $0.003 charge, the supported chain set, the fallback semantics for unknown selectors and events (decoded:false with raw data retained), and the billing exception for provider failures. Those are exactly the behavioral traits an agent needs before paying for a call.

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?

Three tight sentences with the price front-loaded, then scope, then failure/fallback behavior. Every sentence carries distinct information and nothing is repeated from the schema.

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?

The tool is simple (3 required params), has an output schema, and has annotations covering the safety profile. The description fills the remaining gaps an agent would care about: cost, chain coverage, and the fact that undecodable data is returned rather than erroring.

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 all three parameters, making 3 the baseline. The description adds some value by expanding the chain IDs into human-readable network names, but says nothing extra about abi or txHash 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?

States a specific verb and resource: decode a transaction plus its ordered event logs using a caller-supplied ABI. It also names the supported chains and the cost, so an agent can distinguish it from sibling tools like chain_logs or gas_preflight without inspecting either schema.

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 makes the usage context inferable (you need a tx hash and an ABI), but it never states when to prefer this over alternatives such as chain_logs, nor any preconditions or exclusions. Usage is implied rather than guided.

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