domain_allowlist_update

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

With no annotations provided, the description carries the full transparency burden. It does disclose key behavior via 'Replace' and 'clear', implying a destructive overwrite. However, it omits permissions, reversibility, and side effects beyond the basic replace action.

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 two short sentences with no redundant information. It front-loads the core action and adds a clear usage tip, making every word earn its place.

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 simple replace tool with complete parameter schema, the description covers the essential behavior. It does not include alternative guidance or prerequisites, but this is partly mitigated by the explicit name and sibling list. A small gap remains regarding when to prefer this over denylist update.

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 coverage is 100%, with both 'domain' and 'allowlist' already documented in the input schema. The description adds no new parameter meaning beyond reinforcing the empty-list-clears behavior already stated in the allowlist parameter description.

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 'Replace a domain's sender allowlist' with a specific verb and resource. It distinguishes itself from sibling tools like domain_denylist_update and domain_update by explicitly naming the 'sender allowlist' as the target.

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 is given on when to use this tool versus alternatives. The phrase 'Pass an empty list to clear it' is a usage tip but does not help an agent decide between this and domain_denylist_update or other domain update tools.

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