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

Annotations already signal a non-read-only, non-idempotent, non-destructive write. The description adds genuinely new behavioral context: the ownership-verification round-trip, the fact that a repeat call is required to activate, and that sales settle via Escrow.com. It does not cover failure/auth conditions or what happens if the TXT record is missing, so it is useful but not exhaustive.

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?

Four tight sentences: purpose first, then the workflow, then the price-visibility distinction, then the escrow detail. No filler and the ordering matches how an agent would reason about invoking the tool.

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 no output schema, the description correctly explains what the first call returns (a DNS TXT record), which is the key missing return-value context. It omits the withdraw and listing_key paths and does not describe the terminal success state beyond "activates the listing," but for a 6-param mutation tool it is nearly complete.

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 low (33%) so the description must compensate, and it does explain asking_price (visible to buyers) and floor_price (auto-accept threshold, never shown) meaningfully. However, withdraw and listing_key behavior is left largely to the schema, and floor_price's automatic-acceptance semantics are only half-explained, leaving the low-coverage gap partly unfilled.

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 ("List a domain the user owns for sale") that cleanly separates it from siblings like search_domains_for_sale (buying) and make_offer. The ownership constraint is explicit and front-loaded, so an agent can route correctly without opening the 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 lays out the two-step activation workflow clearly: first call yields a DNS TXT record, and a second call with the same domain and email activates the listing once it is added. It gives strong when-and-how context but never names the alternative tools (e.g., make_offer or withdraw flows), so it stops short of explicit when-not guidance.

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