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

Annotations already indicate mutation (readOnlyHint=false) and non-destructive nature (destructiveHint=false). The description adds the approval token requirement, the exact error format for approval_required, and the reassurance that nothing is deleted. This goes beyond annotations and is helpful, though it does not cover edge cases like idempotency or existing state.

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?

Two sentences with no fluff. The purpose is front-loaded, followed by the critical approval flow and a safety note. Every word earns its place.

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?

Given the lack of an output schema, the description covers the key behavioral aspects: the approval error response, the safety guarantee, and the dashboard equivalence. It does not describe the success response or behavior on an already-paused campaign, but for a simple pause action this is minor and not critical for correct invocation.

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 50% (approval_token has a description, campaign_id does not). The tool description explains the campaign_id as the target and the approval_token's role in the guarded flow, effectively compensating for the missing schema detail and adding context beyond the raw schema.

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 ('Pause'), a specific resource ('an active campaign'), and the effect ('stops future sends; nothing is deleted'). This clearly distinguishes it from siblings like resume_campaign and launch_campaign without needing to inspect them.

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 description explains the two-step approval flow and that it's equivalent to a dashboard action, providing clear context for when to use it. However, it does not explicitly name alternatives or conditions like 'use resume_campaign to undo', so it lacks explicit when-not guidance.

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