domains_activate

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

Describes the effect (switching from managed fallback to custom domain) and prerequisite (checks passed). However, without annotations, more disclosure on authorization, reversibility, or side effects would be beneficial.

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?

Extremely concise two sentences with no wasted words. Front-loaded with the action and purpose.

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 for a simple activation tool with only two parameters and no output schema. Explains purpose, prerequisite, and effect. Lacks discussion of error conditions or return values, but not essential.

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% and already describes the two parameters. The description does not add additional meaning beyond what the schema provides.

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 action (activate) and resource (custom mailbox addresses), and distinguishes from siblings by specifying the prerequisite and state change from fallback to custom domain.

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?

Implies when to use (after receive checks pass) but does not explicitly state when not to use or mention alternatives. No exclusions or comparison with siblings like domains_apply or domains_ensure.

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