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

Annotations already declare destructive/openWorld/non-readOnly, but the description adds real behavioral detail: the call consumes a stored plan keyed by approval_ref and expected_plan_digest, rejects other operation kinds before reserving or applying anything, and can affect ad spend. That is meaningful context beyond the structured fields, though reversibility is still unstated.

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 tight sentences with the approval precondition front-loaded and no filler. Every clause adds information about gating, scope, or side effects.

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?

An output schema exists, so return values need not be described. For a destructive external mutation the description covers gating, plan binding, and spend impact, but omits whether the change is reversible and whether partial field updates are permitted.

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 must carry the burden. It partially does — it explains that approval_ref selects the stored plan and that expected_plan_digest gates integrity — but connection_context is never mentioned and no format or failure semantics are given for the digest mismatch case.

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: replace title/body/description on one existing Meta ad. It does not, however, differentiate itself from near-identical siblings such as operations_confirm_ad_copy, operations_confirm_ad_grouped_copy, or ads_update_copy_confirm, so an agent still has to infer which one applies.

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 'After explicit user approval' gives a clear precondition for calling it, which is genuinely useful gating context. But it never names the sibling that produces the plan (ads_update_copy_prepare) or the reject path (operations_deny_approval), leaving the agent to infer the workflow.

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