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

Annotations declare readOnlyHint=false, openWorldHint=true, destructiveHint=false, so the description doesn't need to repeat safety. It adds the key non-obvious behavior that media may be uploaded to Meta and that confirmation is a separate step, going beyond annotations. It doesn't mention permissions or what the prep returns, but with annotations and an output schema, this is a solid 4.

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?

Two short sentences, front-loaded with the action and a crucial side-effect warning. No wasted words, though the extreme brevity means some necessary detail is omitted, which is more an under-specification issue than verbosity.

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 9-parameter mutation tool with 0% schema coverage, the description is too sparse. It omits parameter guidance, preconditions, and the prepare/confirm workflow context, leaving the agent to infer too much from an output schema that describes only results, not inputs.

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 description coverage is 0% (9 params, none documented), so the description carries full burden. It mentions no parameters at all—not ad_id, ad_account_id, nor the multiple page ID fields—and doesn't clarify their relationship. This is a significant gap for a 9-param tool.

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 verb and resource ('Prepare page swap') but is terse and doesn't distinguish it from siblings like ads_replace_creative_prepare or ads_replace_page_confirm. 'Page swap' is clear enough, but the tool's specific role in the prepare/confirm workflow is only implied.

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 phrase 'Confirm separately to apply' signals that this is a preparatory step and that ads_replace_page_confirm is required to finalize, which is useful. However, it doesn't explicitly state when to use this versus other prepare tools or what preconditions must hold.

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