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

The annotations already indicate destructive behavior (destructiveHint: true), and the description adds no extra context about side effects, idempotency, or what happens if the instance is already assigned. The description simply repeats the action without providing any behavioral details.

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 redundant, repeating the same idea twice ('Add instance to a Private Network' and 'Add a specific instance to a Private Network'). This wastes space without adding meaningful information, making it less concise than a single well-worded sentence would be.

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 destructive tool with no output schema and minimal annotation, the description is severely incomplete. It does not mention return values, error conditions, prerequisites (e.g., existing network or instance), or any consequences of the operation. This is insufficient for an agent to safely and correctly use the tool.

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?

The schema has no parameter descriptions (0% coverage), and the description does not explain any of the parameters. It only mentions 'instance' and 'private network', which are already obvious from the parameter names, and gives no clarity on x-request-id or x-trace-id. The description fails to compensate for the missing schema metadata.

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 clearly states the action ('Add') and the resources involved ('instance' and 'Private Network'), making it obvious what the tool does. It also distinguishes from the sibling tool 'unassignInstancePrivateNetwork' by describing the opposite operation.

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?

The description provides no guidance on when to use this tool versus alternatives, nor any prerequisites or exclusions. For example, it does not mention the sibling 'assignIp' or 'createAssignment' tools, making it unclear what unique scenario this tool is for.

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