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

Annotations already declare this is a non-read-only, open-world, non-idempotent, but non-destructive write. The description adds useful context beyond that: the request is 'Free and non-billable' and collection is prioritized 'based on demand,' implying asynchronous handling. It does not explain what the immediate response looks like or how the agent learns when the signal becomes available.

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, followed by the usage condition and the cost/prioritization note. Every sentence carries distinct information and there is no filler.

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 three-parameter submission tool with full schema coverage and helpful annotations, the description covers purpose, when to use it, cost, and the demand-driven collection model. It could be more complete by noting that no data is returned immediately or how the requester will be notified, but the essential calling context is present.

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 the schema already documents domain, signal, and note with examples. The description only restates 'exactly what signal you need for a domain' without adding format or validation guidance, 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.' It makes clear this is a request-submission tool rather than a data-retrieval one, which distinguishes it from the many get_* siblings. It stops short of naming the most similar sibling (request_new_brand_monitoring) to sharpen the boundary.

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 an explicit when-to-use condition: 'For a signal that is missing for a domain or that RivalSweeper does not track yet.' That tells the agent to reach for it only when existing data tools cannot satisfy the need. It does not name alternatives or exclusions, so it falls short of a 5.

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