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

With no annotations, the description carries the burden of disclosing risk. It clearly warns that calls are REAL, that credits are charged per call minute, and that preview approval is required. It stops short of explaining permissions, irreversibility, or behavior on insufficient credits, so it is strong but not exhaustive.

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?

Three sentences, front-loaded with the core action and cost warning. Every sentence adds distinct value: purpose, preview prerequisite, and pause alternative.

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?

The description covers purpose, cost, approval prerequisite, and pause routing, which is adequate for a high-risk mutation. However, with ten parameters at 10% schema coverage and no annotations or output schema, it omits parameter semantics and several safety details an agent would need.

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 only 10% (only id is documented), so the description should compensate for the ten parameters. Instead it defers with 'Same args as preview_activate_campaign_phone', which is a useful pointer but leaves timezone, call_objective, talking_points, phone_number_ids, max_calls_per_day, working hours, and max call duration unexplained.

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, resource, and scope: scheduling REAL outbound AI calls to every audience contact with a phone number. It distinguishes itself from preview_activate_campaign_phone via the approval condition and names pause_channel as the control alternative.

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 key precondition: use only after the user approved preview_activate_campaign_phone. It also names pause_channel channel=phone_call as the tool to use for pausing, giving a clear alternative action.

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