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

Beyond the annotations, the description adds substantial behavioral context: exact $0.05 USDC payment on Base, 30-day duration, HTTP 402 origin verification, the payTo address, and the overwrite/extension side effect on re-registration. This is strong disclosure for a mutating paid tool.

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 entry is compact and front-loaded, packing payment, duration, verification, side effects, and payTo into a few short sentences with no filler. The REST POST equivalence at the end is somewhat cryptic, but the overall structure is efficient.

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 paid mutation with no output schema, the description covers price, destination, duration, verification, and side effects. However, the payment flow is ambiguous: it doesn't clarify whether the tool charges automatically or whether the caller must send USDC separately, and it doesn't mention using name_lookup to check existing names before registering.

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 schema already documents all parameters. The description adds meaningful semantics for name by explaining that re-registration overwrites or extends, and for origin by requiring https and HTTP 402, though ownerHint receives no extra explanation beyond the schema.

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 action and resource: register or extend an ENS-style agent name for 30 days, with an exact price. This clearly distinguishes it from read-only siblings like name_lookup, though it never names that alternative explicitly.

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 payment and verification requirements clear, and implies use when a paid 30-day name registration or extension is desired. It provides no explicit when-not-to-use guidance or pointer to name_lookup for checking existing names, so sibling routing is left mostly to inference.

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