assign_instance_firewall

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

Annotations already declare readOnlyHint=false, idempotentHint=false, openWorldHint=true and destructiveHint=false, so the mutation profile is covered. The description adds nothing beyond the endpoint path: no statement of what happens if the instance is already assigned, no error behavior, and no note that the call is non-idempotent.

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?

Very short and front-loaded, but the second line repeats the first almost verbatim ('Add instance to a firewall' vs 'Add a specific instance to a firewall'), so one sentence is wasted.

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?

Adequate minimum for a simple 2-required-param mutation with full schema coverage and annotations, and no output schema to explain. It falls short on lifecycle questions an agent would care about — idempotency on repeat calls and error conditions — that neither the schema nor annotations cover.

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 firewallId and instanceId are documented in the schema, including the int64 type of instanceId. The description adds no meaning beyond the endpoint template, so the baseline of 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?

Clearly states the verb and resource: add a specific instance to a firewall, plus the REST endpoint POST /v1/firewalls/{firewallId}/instances/{instanceId}. The pairing with the sibling unassign_instance_firewall is inferable from the name, though the description never names it.

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?

No guidance on when to use this versus alternatives such as unassign_instance_firewall or the private-network equivalent assign_instance_private_network, and no stated prerequisites (e.g., firewall and instance must already exist). Usage is only implied by the name.

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