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

Beyond the sparse boolean annotations, the description discloses the one-time dns_token, 24-hour expiry, inability to extend, fact that the name is assigned rather than chosen, and the PSL/certificate-sharing caveat. These are exactly the non-obvious behaviors an agent needs to avoid misusing the 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?

The definition starts with the core action and duration, then follows with use cases and constraints in a logical order. Every sentence adds a distinct, load-bearing fact; none repeat the schema or annotation data.

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 one-shot ephemeral naming tool, the description covers lifecycle, output characteristics, security implications, and boundary conditions ('without it the name cannot be changed or removed'). An agent has enough context to call it directly and interpret the result even before seeing the output schema.

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 input schema already covers both parameters with descriptions, so the baseline applies; the description adds usage context rather than new parameter syntax. Its 'address you already control' phrasing reinforces the required ip field but does not change the mechanics documented in the schema.

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 names a specific verb and resource ('Point a public hostname at an address') with a clear temporal scope ('for 24 hours'), making the tool's core function unmistakable. It also distinguishes this from the sibling read/update/delete DNS tools by describing a fixed one-shot, auto-expiring naming service.

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 gives explicit use cases ('a webhook target someone has to type, a staging box whose address moves') and tells the agent what it is not for ('no tunnel, no hosting, no certificate and no HTTPS'). It does not name sibling tools as alternatives, but the when-to-use guidance is strong enough to route correctly.

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