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

Discloses non-obvious traits beyond the annotations: a single id triggers a live re-screen and may fire a webhook, multi-id calls return cached 6-hourly statuses, unknown ids surface as not found, pricing differs by cardinality, and failed calls are not charged. This explains why readOnlyHint is false and why the call is not free, which the structured fields alone could not convey.

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?

One dense paragraph, front-loaded with purpose before branching into cardinality, alternatives, errors, and pricing. Every sentence carries information, though the payment and failure clauses could be broken out for faster scanning.

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 an output schema present, return values need no explanation, and the description covers the remaining agent-relevant unknowns: pricing, x402 payment failure mode, stale-vs-live semantics, and unknown-id handling. Nothing needed to invoke it correctly is missing.

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% and the schema description already states the 1-vs-2-20 behavioral split, so the baseline would be 3. The description nonetheless adds value the schema lacks: the cost differential between one and many ids and the freshness/re-screen distinction tied to the same parameter.

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 precise verb+resource ('Read the status of watchlist monitors') and immediately ties it to the create_watchlist_monitor lifecycle, so the agent can place it in the watchlist family 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?

Explicit routing: one id for a fresh pre-action answer, 2-20 for a periodic sweep, screen_entity/screen_wallet for entities without a monitor, cancel_watchlist_monitor to stop monitoring. This is exactly the when/when-not/alternatives structure the dimension asks for.

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