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

With no annotations present, the description carries the full burden, and it does add real behavioral context: per-action credit costs by blockchain and the fact that actual credits spent are returned in response headers. It does not state that both operations are read-only/safe or mention authentication needs, which leaves a gap for a no-annotation tool, but the cost disclosure is substantive.

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?

Purpose is front-loaded in the first line, then structured under clear headers. The two credit bullets are near-identical and could be merged, and the closing disclaimer about credits being indicative is slightly verbose, but overall the layout is scannable and earns its space.

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?

There is no output schema, so the description should ideally describe what a decode-raw-transaction result contains (decoded fields) or what validate-address returns, and it does neither. Inputs, networks, and costs are well covered, but the return side of a decode operation is left entirely to inference.

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 coverage is 100%, so the baseline is 3, but the description adds genuine value the flat enums cannot: it maps which networks belong to which blockchain (ethereum → mainnet/sepolia, tron → mainnet/nile, etc.), resolving the combinatorial ambiguity of independent blockchain and network enums. The credit table also ties action+blockchain combinations to cost.

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 names a specific resource (EVM utilities) and enumerates its two concrete operations with one-line explanations ('validate-address: Check if an EVM address is valid'). This clearly separates it from sibling utils tools like utils__utxo_utils and utils__xrp_utils by chain family. It stops short of explicitly stating the contrast, but the verb+resource is unambiguous.

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 action list implies which operation to pick for a given task, but there is no explicit when-to-use/when-not-to-use guidance and no statement of prerequisites (e.g., that address is needed for validate-address, rawTransactionHex for decode). The schema does mark these as conditional requirements, so usage is inferable rather than stated.

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