ads_register_slot

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

With no annotations, the description carries the full burden, and it does disclose real behavior: registration is free, no payment is required to list, price_usd sets a daily rate, weekly/monthly tiers are generated automatically, and buyer-side payment is not yet automated. That is meaningful beyond what structured fields provide. Gaps remain on auth/wallet requirements, idempotency or duplicate handling, and any rate limits.

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 clause, followed by pricing behavior, return value, and the payment caveat — a sensible ordering for a registration call. The closing sentence ('buyers pay you is not yet automated') is grammatically awkward and could be tightened, but it still carries an important expectation-setting limitation.

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 description covers the create-once purpose, the return shape (slot_id plus integrate URL), and the next tool call, which offsets the missing output schema. However, for a 9-parameter mutation tool with no annotations and zero schema documentation, seven field meanings are wholly unexplained, leaving an agent unable to supply a correct payload beyond the required trio.

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 0% across 9 parameters, so the description must compensate and largely does not. Only price_usd ('your daily rate') and implicitly property are given meaning; name, format, wallet, contact, audience, placement, and description are left entirely undefined in both schema and prose.

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 and resource — 'List your own site ... as x402ads inventory' — and immediately situates the tool relative to ads_browse (discovery) and ads_integrate (embed script retrieval). An agent can distinguish it from the many sibling ads_* tools without opening any 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?

Clear context for when to use: you have a site you operate and want it discoverable as ad inventory. It also gives explicit next-step routing ('call ads_integrate with that slot_id'), which is genuinely useful. It stops short of stating exclusions, such as what to do if a slot already exists or whether re-registration is allowed.

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