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

Annotations already declare readOnly, non-destructive, closed-world behavior, so the bar is lower. The description adds genuine value beyond that: ownership scoping and a disclosure of the returned row shape (source_adgroup_id plus source_adset_id aliases).

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?

Front-loaded with the core action, followed by the aliasing rationale and a concrete example. Efficient overall, though the dual-key explanation is slightly verbose for a read tool.

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?

With no output schema, the description usefully sketches the returned row's keys, and with annotations covering safety there is little else an agent needs. Only the optional connection_context parameter is left unaddressed.

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 coverage is 0%, so the description must compensate. It documents the required interest_pack_id as a str UUID sourced from interests_list and shows a call example, though it leaves the optional connection_context undocumented.

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+resource (get one saved interest pack) with an explicit scoping constraint (owned by the authenticated user, keyed by interest_pack_id). It is clearly distinguishable from siblings like interests_list, interests_archive, and interests_fetch_from_adset.

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 signals the retrieval workflow by telling the agent the ID is a 'UUID from interests_list' and that the pack must be owned by the authenticated user. There is no explicit when-not-or-alternatives guidance, but the context is clear.

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