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

The description discloses a significant side effect that annotations do not cover: charging an upgrade if pending keywords exceed the current plan. It also states the promotion behavior (free for what fits) and the return value, giving the agent a complete behavioral picture.

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?

The description is three sentences with no wasted words. The core purpose is front-loaded, and each sentence adds distinct value: what it does, how billing works, and what to do first.

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?

Given that there are no parameters and an output schema exists, the description covers all necessary context: the activation behavior, the potential charge, the preview recommendation, and the return value. An agent has enough information to invoke this tool correctly.

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?

The tool has zero parameters, so the schema is exhaustive and there is nothing for the description to add about parameter semantics. The baseline of 4 applies because no parameter documentation is needed.

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 action ('Activate PENDING keywords') and clearly distinguishes this batch activation from sibling tools like enable_keyword or add_keywords. It also explains the outcome (returns updated websites), making the tool's role unambiguous.

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?

The description explicitly tells the agent to use preview_activate_pending first to see the cost, which is a direct usage guideline and alternative routing. It also implies this tool is the actual activation step, making the relationship to the preview sibling clear.

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