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

Annotations already declare destructiveHint=true and idempotentHint=false, so the safety profile is covered. The description adds genuine behavioral context beyond them: confirm=false triggers a dry-run preview, and the API limitation on HIDDEN/REMOVED states. It stops short of describing reversibility or auth/permission requirements.

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?

Content is front-loaded with the core operation, then the sibling redirect, then role semantics, then the API limitation and dry-run flag. It is information-dense and every clause earns its place, though the single long paragraph is slightly heavy for a 4-parameter tool.

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. The description covers purpose, the alternative tool, role semantics, the API's limitation, and dry-run behavior — everything an agent needs to invoke this mutation correctly.

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 0%, so the description carries the parameter burden. It richly explains 'role' (PRIMARY vs SECONDARY with consequences for Conversions column and smart bidding) and 'confirm' (dry-run). However, customer_id and conversion_action_id receive no explanation, leaving half the parameters undocumented.

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 and resource (makes a conversion action PRIMARY/SECONDARY) and defines the operation precisely, including what 'role' controls. It cleanly distinguishes itself from the sibling set_conversion_settings by naming what that tool handles instead.

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?

It explicitly routes the agent: to change default VALUE, counting or lookback window, use set_conversion_settings instead. It also flags the boundary condition — pausing/removing a conversion action cannot be done via this API and must be done from the panel.

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