create_callouts

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

With no annotations provided, the description carries the full burden and does well: it discloses the non-idempotent retry behavior (a retry re-runs ALL steps, re-adding extensions), the partial-failure state (association raises after library add lands), and that the error carries extension_ids for reconciling. This is genuinely useful beyond the schema. The only minor gap is no statement of the return shape on success.

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?

Three short sentences with the main purpose front-loaded; the failure-mode detail is dense but earnestly informative and not padded. Slightly tighter if the 'Live-verified' timestamp were dropped, but overall well-proportioned.

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 2-param tool with no annotations, no output schema, and 0% schema coverage, this description covers purpose, a key constraint, and a critical failure trap — a good start. But it omits campaign_id semantics and any usage-vs-alternative direction, and gives no indication of the success response. Both required params are touched only partially.

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, and it does for `texts` by adding the 25-char-per-item constraint. But it says nothing about the required `campaign_id` parameter — its meaning, how it maps to an account, or whether it must reference an existing campaign. Half the parameters remain effectively 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?

The description states a specific verb ('create'/'Draft') and resource ('callout extensions') with a concrete constraint (max 25 chars each), and it is visually distinguishable from siblings like draft_sitelinks and create_structured_snippets, which are different extension types. However, it does not explicitly name or contrast itself against those siblings, relying on the user's understanding of ad-extension taxonomy.

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 on when to use this tool versus alternatives such as list_extensions (to check existing callouts), remove_extension (to delete), or draft_sitelinks (for a different extension type). The mid-apply failure note is behavioral, not usage direction, so an agent gets no help deciding whether create_callouts is the right tool in a given flow.

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