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

Annotations already declare destructiveHint=true, readOnlyHint=false, and idempotentHint=false, so the safety profile is covered. The description adds real precondition context (authenticated native buyer, existing funded placement), but never states the consequences of stopping — whether it is reversible, what happens to the running policy, or how the 409/stale-version path behaves at the tool level.

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 short sentences, zero filler, and the action is front-loaded before the prerequisite clause. Every clause carries information.

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?

For a 2-parameter destructive mutation with no output schema, the description covers the identity of the operation and its prerequisites but omits outcome information — what stopping actually does to spend/placement, reversibility, and error handling — which an agent deciding whether to invoke a destructive tool would want.

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 both parameters are fully documented in the schema, including the 409-on-stale-version behavior for expected_version. The description adds a conceptual framing ('at the expected policy version') that hints at optimistic concurrency but no syntax or format detail beyond the schema, so the baseline 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 uses a specific verb+resource pair ('Stop the native experiment') and scopes it to a policy version, which is far more informative than a tautology. It does not, however, name its siblings (create_creative_experiment, get_creative_experiment, update_creative_policy), so an agent must infer the lifecycle position from the verb alone.

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?

'Stop the native experiment at the expected policy version' plus the note about an 'authenticated native buyer and existing funded placement' implies the preconditions for calling it, which is genuine usage context. There is no explicit when-to-use vs. alternatives guidance and no exclusion cases (e.g., what to do for non-native experiments).

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