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

With no annotations, the description carries the full burden and meaningfully discloses that this only prepares an unsigned transaction payload and requires a user wallet signature. This prevents the agent from assuming the tool broadcasts the transaction. It does not detail overwrite behavior or response shape, but the unsigned/signature distinction is high-value transparency.

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 sentence packs the key facts: what is prepared, the action (set/update), the resource, the network, and the required signature. No filler or redundant restatement of the tool name.

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 two-parameter tool with no output schema, the description covers the main action and an important prerequisite (signature). However, it does not say what the returned payload looks like, whether an existing primary domain is replaced, or whether there are constraints on the domain/wallet relationship. These gaps are notable but not fatal.

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?

The schema already describes both parameters at 100% coverage: domainName is a .i domain and ownerAddress is a 0x EVM address. The description adds no further parameter-level meaning beyond the schema, so the baseline of 3 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?

The description uses a specific verb-resource combination: 'Prepare an unsigned transaction payload to set or update the primary reverse resolution domain identity.' It also names the network (Arbitrum One) and the target ('given wallet address'), making the tool's function concrete and distinguishable from siblings like resolve_domain_identity or register_domain.

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 provides clear context for when to use the tool: when the user wants to set or update the primary reverse resolution domain for a wallet on Arbitrum One. It does not explicitly name alternatives or when-not conditions, so it stops short of a 5.

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