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

Annotations already declare destructiveHint=true and openWorldHint=true, so the safety profile is known; the description adds real value by disclosing the validate-before-reserve/apply ordering, that state changes are external to Meta, and that spend may be affected. It still doesn't say whether the change is reversible or what auth/permission scope is needed.

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 compact sentences with the approval precondition front-loaded and the scope constraint following. No filler, though the clause about rejecting other operation kinds is slightly dense.

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 destructive external mutation with annotations and an output schema present, the description covers precondition, scope, validation ordering, and side effects. Coverage is only incomplete on the unexplained connection_context parameter.

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%, so the description carries the full burden. It explains that approval_ref and expected_plan_digest select the stored plan and are used exclusively, which is meaningful semantics, but it says nothing about connection_context and gives no format or failure behavior for the two named parameters.

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 and resource: 'change delivery status for the approved batch of Meta ads.' The batch framing implicitly distinguishes it from the singular sibling operations_confirm_ad_status, but the differentiation is never made explicit, so an agent must infer it.

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?

Gives a clear precondition ('After explicit user approval') and a routing rule ('rejects other operation kinds before reserving or applying anything'). It does not, however, name the adjacent alternatives such as operations_deny_approval or operations_confirm_ad_status, so the when-not guidance is left to inference.

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