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

With no annotations, the description carries the full burden. It usefully discloses that the first observation sets a baseline and that results arrive as private in-app notifications, plus the zero-cost fact. However it says nothing about auth requirements, rate limits, failure behavior, or what happens to the baseline on later runs.

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?

Four short sentences, front-loaded with purpose and cadence, then behavior, then cost. Nothing is padded, though the baseline and notification points could be slightly tighter.

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?

The behavioral arc (baseline then notifications) is adequately conveyed and no output schema exists to explain. But with a nested 'query' object lacking any description and no annotations, an agent still lacks the structural detail needed to construct a valid call.

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% across three required parameters, including a nested object 'query' with no structure defined anywhere. 'daily or weekly' loosely maps to the interval_days enum, but 'query' and 'label' are left entirely unexplained, so the description does not compensate for the coverage gap.

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 specific verb (monitor) and resource (Google Ads or AdSense query) with a clear cadence, and describes the concrete outcome (recording newly observed ads/sites as notifications). It is distinguishable from lookup/search siblings by its recurring nature, though it never names an alternative directly.

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 recurring 'daily or weekly' framing implies when the tool is appropriate versus a one-off lookup, but there is no explicit when-to-use/when-not statement and no sibling is named as the alternative. Usage must be inferred from the cadence wording.

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