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

No annotations are provided, so the description carries the behavioral disclosure burden. It clearly signals a read-only operation ('Get') and adds useful behavioral detail about returning both source_adgroup_id and source_adset_id keys. It doesn't mention error cases or permission specifics, but for a simple fetch this is 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 compact and front-loaded: purpose, key behavioral guarantee, then required parameter and example. Every sentence earns its place, with no filler or repetition.

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 one-parameter read tool with no output schema, the description covers purpose, parameter provenance, and the notable dual-key return behavior. It doesn't detail the full response shape or error conditions, leaving minor ambiguity but no critical gap for basic usage.

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 only says the parameter is a string and provides no description. The tool description compensates by declaring it REQUIRED, specifying it is a UUID from interests_list, and showing a concrete invocation example.

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 ('Get one saved interest pack owned by the authenticated user') on a specific resource identified by interest_pack_id. It also distinguishes itself from siblings like interests_list and interests_fetch_from_adset by emphasizing single-item retrieval by ID.

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?

It gives clear context: use this when you have a specific interest_pack_id from interests_list, and it provides an explicit example call. It doesn't explicitly name when not to use it or compare alternatives, so it falls short of a 5.

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