add_address_group_members

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

With no annotations, the description carries the full burden and does well: it discloses additive semantics, that duplicate member names are skipped (idempotent behavior), and what the response reports. It omits permission requirements and what happens if a named address object does not exist, which matters for a mutation tool.

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?

Front-loaded with purpose, then a use case, then labeled Parameters/Returns sections. The parameter list largely restates the schema, a small redundancy, but the overall length is tight and every other line 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 4-parameter mutation tool with no annotations and no output schema, the description covers add-vs-replace semantics, duplicate handling, and return contents. Missing failure modes (nonexistent member objects, invalid group name, device/vdom mismatch) keep it from being fully complete.

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 the baseline is 3; the description earns an extra point by adding the 'already-present names are skipped' semantics for members and noting that vdom is optional. It adds no format or constraint details beyond that.

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 opening sentence states a specific verb (add), resource (address objects), target (existing address group) and a critical scope constraint (keeping current members). This cleanly distinguishes it from remove_address_group_members and create_address_group in the sibling list.

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 'Typical use' paragraph gives a concrete scenario (exempting a new host that a policy already governs) and implicitly steers the agent away from editing the policy directly. It stops short of explicitly naming the alternative tools (e.g. remove_address_group_members, update_firewall_policy) or stating when not to use it.

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