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 covered. The description adds real value beyond them: it discloses that changes affect external Meta state and 'may affect spend', and that other operation kinds are rejected before reserving or applying anything.

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 dense sentences, front-loaded with the action and the approval precondition. Every sentence carries information — mechanism, guard behavior, and impact — with no filler.

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, and annotations cover the destructive/open-world profile. The main remaining gap is the undocumented connection_context parameter and the lack of any sibling disambiguation for a mutation tool in a crowded operations_confirm_* family.

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 load. It gives semantic meaning to approval_ref and expected_plan_digest (they select the stored plan to apply) but says nothing about connection_context or the digest/format expectations, leaving one of three parameters undocumented everywhere.

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 and resource: 'replace the creative on one existing Meta ad', which is concrete and unambiguous. It does not, however, differentiate itself from the near-identically named sibling ads_replace_creative_confirm, which an agent could easily confuse with this operations_confirm_* tool.

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?

'After explicit user approval' establishes a precondition, and the description scopes input to 'the stored plan selected by approval_ref and expected_plan_digest'. It never names or rules out the sibling prepare/confirm/deny tools, so the routing decision 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.