get_ad_stats

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

Annotations already cover read-only, idempotent, non-destructive behavior. The description adds valuable behavioral detail beyond annotations: the exact time-bucketing semantics, the supported metrics, and the differing date ranges for each period value. This helps the agent predict what the tool will actually return.

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 compact and well-structured: an initial summary line followed by the two relevant period behaviors. Every sentence adds useful information with no filler or redundancy.

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, read-only, two-parameter stats tool with an output schema and strong annotations, the description is sufficient. It explains metric coverage, period-specific behavior, and default context. Return value details are already covered by the output schema, so nothing critical is missing.

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 description must carry parameter meaning. It fully explains the 'period' enum semantics with examples, which is the main non-obvious parameter. The ad_id parameter is self-evident from the schema and tool name, so not explaining it is acceptable.

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 clearly identifies the resource and function: retrieving ad statistics broken into time buckets with specific metrics (CTR, CPC, actual CPM). The 'time-bucketed' qualifier separates it from simpler sibling tools like get_ad or get_ads.

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 gives concrete guidance on choosing between the two period values: '5min' covers the last 24 hours, while 'day' covers full lifetime daily stats. It does not explicitly name alternatives or exclusions, but the context is clear enough for correct tool selection.

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