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

With no annotations, the description carries the full burden, and 'List supported deep-analysis families' clearly indicates a read-only enumeration operation with no side effects. It does not describe output format or error behavior, but for a zero-parameter listing tool, the disclosed behavior is largely sufficient.

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 a single, front-loaded sentence with no filler. Every word contributes meaning: 'supported', 'deep-analysis', and 'families' all specify the scope of the list operation.

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 zero-parameter enumeration tool, the description is nearly complete: it states the operation and the resource. The only minor gap is the absence of an output schema or explicit mention of the return shape, but 'List families' strongly implies an array of family names or identifiers.

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?

There are zero parameters and the schema is empty, so there is no parameter semantics for the description to clarify. Per the baseline for zero-parameter tools, this is adequate.

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 uses a specific verb ('List') and a specific resource ('supported deep-analysis families'), making the tool's function immediately clear. No sibling tool covers 'families', so it distinguishes itself from the other list tools without needing extra context.

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 intended use is implied: call this tool when you need to know which deep-analysis families are supported. However, it provides no explicit guidance about when to prefer it over related deep-analysis tools like google_ads_deep_analysis_query or google_ads_deep_analysis_export, nor does it mention any alternatives.

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