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

Annotations already declare idempotentHint=true, destructiveHint=false, and readOnlyHint=false, so the safety profile is covered. The description adds a useful behavioral nuance — that only future sends are halted, not past ones — but says nothing about required campaign state, error behavior, or permission needs. It adds modest value on top of annotations.

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?

A single, front-loaded sentence with no wasted words. It is efficient, though the 'APP:' prefix is noise and the brevity comes partly at the cost of needed detail.

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 explained, but the definition leaves the seven undocumented input parameters, the campaign-state preconditions, and the pause-vs-cancel distinction entirely unaddressed. For a mutation tool with rich, ambiguous parameters this is insufficient.

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?

The schema has 7 parameters at 0% description coverage, and the description explains none of them. In particular the relationship between id / campaignId / externalCampaignId and the purpose of idempotencyKey and the external* correlation fields is left entirely opaque, so the description does not compensate for the coverage gap at all.

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 gives a specific verb ('Pauses') and a specific resource scope ('future sends for an outbound email campaign'), so the core action is unambiguous. It does not, however, distinguish this from close siblings such as cancel_campaign or resume_campaign, which is what would be needed for a 5.

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?

There is no guidance on when to pause versus cancel, delete, or resume a campaign, nor any stated prerequisites or state conditions. The agent must infer the operational context entirely from the name.

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