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

Annotations already declare this is a non-destructive, open-world, non-idempotent submission; the description goes further with the operationally important fact that it is 'Free and non-billable' and that fulfillment is demand-prioritized (i.e., no immediate data return). It stops short of saying what the caller receives back or expected turnaround.

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?

Three short sentences, front-loaded with the core action, then the routing condition, then the cost caveat. No filler and nothing repeated from the title or schema.

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 request-submission tool with no output schema, the description covers the essentials: what to submit, when, and that it costs nothing. It leaves a small gap around what the response confirms (acknowledgement vs. request ID) and how/when the requested signal becomes available.

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 100%, so domain, signal, and note are already fully documented including example signal values. The description only restates that the request is scoped to a domain and adds no syntax, format, or constraint detail beyond the schema, so baseline 3 applies.

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 verb and resource: 'Tell RivalSweeper exactly what signal you need for a domain,' clarifying it is a demand/request submission rather than a retrieval. It ties itself to a named sibling (check_brand_data_coverage), but does not distinguish itself from the other request-style sibling, request_new_brand_monitoring.

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?

It gives two concrete triggers: 'when check_brand_data_coverage shows a signal is missing' and 'when you need data we do not yet track.' That is a clear when-to-use with a named upstream diagnostic tool, but there are no explicit exclusions or an alternative to prefer for adjacent cases (e.g., a brand not yet tracked).

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