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

Annotations already declare non-read-only, non-destructive, open-world, and non-idempotent behavior. The description adds that pairing is the only effect—removes and submits nothing—and that no confirmation is required, which meaningfully reduces the risk of invoking it for the wrong operation. It still does not clarify return behavior or idempotency details beyond the 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?

The description is front-loaded with scope and action, then gives the key precondition and exclusion. Every clause earns its place, including the operational note that no confirmation is needed.

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 pairing mutation with no output schema, it supplies the core precondition and non-effects. It leaves open what pairing returns, how project_id scopes the operation, and how this tool relates to pre_pair_marketplace_items or submit_ad_items.

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?

Only ad_id is documented in the schema, as the integrationId from list_ads; project_id has no schema description. The tool description provides no parameter guidance at all, so it does not compensate for the 50% schema coverage gap.

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 names the specific action (pre-pair), the target resource (AD-wide existing channel listings with Koongo items), and explicitly excludes removal and submission. 'AD-wide' also separates it from the marketplace counterpart in the sibling set.

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 states a clear precondition: use this when the channel already holds listings. It also says no confirmation is needed, but it does not name an alternative for channels without listings or explain explicit when-not cases.

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