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

The annotations already mark this as a destructive, non-read-only mutation, so the description does not need to repeat that safety profile. It adds the useful constraint 'within its original expiry,' but it does not explain what revision invalidates, how the expected plan digest is used, or what happens if the approval has expired.

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?

The description is a single front-loaded sentence with no filler. It is perhaps too terse for a destructive tool with a complex nested patch, but the sentence itself is efficiently structured.

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 tool with three required parameters, a nested patch object, 0% schema description coverage, and destructive behavior, this description is materially incomplete. It says what is revised and that an expiry applies, but omits parameter semantics, revision consequences, and how it relates to the surrounding prepare/confirm workflow.

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%, and the description does not explain any of the three required parameters. It gives no meaning for approval_ref, expected_plan_digest, or the nested patch structure, so it fails to compensate for the schema's lack of parameter descriptions.

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 names a specific verb and resource: 'Revise a prepared create approval.' This distinguishes it from pure preparation or confirmation tools, though it does not explicitly name the sibling alternatives it differs from.

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?

It implies this tool is used on an already-prepared create approval before it expires, which gives some usage context. However, it does not state when to choose this over campaigns_quick_create, confirmation tools, or deny/abandon paths.

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