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

No annotations are provided, so the description carries the full behavioral burden, yet beyond the '(PUT CM API)' hint it says nothing about permissions, reversibility, or whether omitted fields are preserved on a PUT. The pause-via-status behavior is only discoverable from the schema's ENABLED/PAUSED note, not the description.

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 zero filler. It is arguably too terse for a mutation tool with five parameters, but nothing in it is wasted.

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?

This is a mutation tool with no annotations, no output schema, and ambiguous PUT semantics, yet the description omits what changes are applied, whether unmentioned fields are cleared, and what a successful call returns. For a write operation with zero structured safety signals, it does too little.

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 100%, so all five parameters are already documented, including currency defaults and the status enum. The description adds no syntax, format, or interaction detail beyond what the schema states, so the baseline of 3 applies.

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 concrete verb and resource ('Update campaign status and/or daily budget') and usefully corrects the misleadingly narrow tool name enable_campaign, which alone would suggest only enabling. It does not differentiate from siblings like create_campaign, delete_campaign, or update_ad_group, leaving an agent to infer scope from the name.

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?

No when-to-use, when-not-to-use, or alternative-tool guidance is given beyond the implicit fact that this mutates an existing campaign. An agent must guess whether to reach for this versus create_campaign/duplicate_campaign or update_ad_group for related edits.

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