get_ad_performance

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

With no annotations available, the description must disclose behavioral traits, but it only states the bare noun phrase. It does not reveal what 'performance' means, whether data is aggregated, any rate limits, or what the return structure looks like. This is a significant gap for a tool with zero annotation support.

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 extremely short but its brevity reflects under-specification, not intentional conciseness. It provides no structure, no front-loading of critical information, and every word is essentially a restatement of the name. It lacks the detail that would make it useful.

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 getter with one optional parameter and no output schema, a minimal description might suffice, but even minimal usage requires knowing what performance data is included and how 'days' relates to it. The description offers none of this, making it inadequate for an agent to invoke correctly and interpret results.

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 schema has one parameter 'days' with no description (0% coverage), and the tool description makes no mention of it. Since the description does not compensate for the schema's lack of explanation, the agent is left without any hint of the parameter's meaning or usage. This is a complete failure to add value.

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 'Per-ad performance.' is essentially a repetition of the tool name 'get_ad_performance', adding no new specificity about what metrics, scope, or verb are involved. It fails to distinguish this from sibling tools like get_campaign_performance or get_keyword_performance, since all are performance getters.

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?

No guidance is provided about when to use this tool versus alternatives. There is no mention of use cases, exclusions, or how it differs from other performance-related tools. An agent receives no signal about when to pick this over similar siblings.

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