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

Annotations already flag this as a non-read-only, non-idempotent, open-world operation. The description adds meaningful context beyond them: it explains the daily polling cadence, the email-notification trigger conditions, and that it returns a watch id and status key. It does not disclose auth requirements or how to cancel a watch, keeping it just short of a 5.

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?

Two tight sentences that front-load the core behavior and place return values last. No wasted words, though it could be slightly tighter given how few concepts it covers.

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 simple two-parameter monitoring tool with no output schema, the description covers what it does, when it notifies, and what it returns. Missing only peripheral details like watch lifecycle/removal, which is minor at this complexity.

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%, so the schema provides no semantics for the two parameters. The description implies email is the notification address ('emails when...') and domain is the watch target, but it never explicitly defines either field, leaving some inference to the agent.

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 gives a specific verb + resource ('checks a domain daily') and clearly states the monitored events (drops, changes hands, listed for sale). It distinguishes itself from siblings like check_availability by describing an ongoing, notification-based service rather than a one-off lookup.

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?

Usage is implied — you call this to set up recurring monitoring and later use the returned status key with broker_status. However, there are no explicit when-to-use/when-not statements, no mention of how it compares to check_availability or make_offer, and no prerequisites stated.

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