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

Annotations already declare readOnlyHint=false, idempotentHint=true and destructiveHint=false; the description goes further by clarifying that approval itself 'sends nothing' (a non-obvious distinction from launching), that a modified draft invalidates prior approval, and that a business-owner authority is required. It is also consistent with idempotentHint=true since approving the same revision is repeatable.

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?

Four short sentences, front-loaded with the action and its scope, then invalidation rule, then the send/no-send boundary, then the authority constraint. No restatement of the title and 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. For a 3-parameter, non-destructive approval gate the definition covers scope, staleness semantics, side-effect boundary, and authorization — nothing an agent needs in order to invoke it correctly is missing.

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 coverage is 100%, so baseline is 3; the description nonetheless adds provenance the schema lacks by tying fingerprint to the exact value returned by draft_email_campaign or get_email_campaign, which tells the agent where to source it rather than guessing. It does not explain formatting of business_id or campaign_id beyond the schema text, so it stops short of a 5.

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 (approves) and a precisely scoped resource (one exact revision of a drafted email campaign), and binds it to campaign_id plus fingerprint. It is clearly distinguishable from draft_email_campaign and launch_email_campaign, which are named as the producers of the fingerprint and the consumer of the approval respectively.

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?

Explicitly states the re-approval condition ('A changed draft has a new fingerprint and needs a new approval'), names the alternative for actually sending ('launch_email_campaign queues it'), and restricts the actor ('Business owner only'). When-to-use, when-not-to-send, and who-may-call are all covered.

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