Create HTTP forward

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

Annotations establish the mutation profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false, openWorldHint=true). The description adds genuinely useful behavioral context beyond that: the operation fails if the host already has a forward or a conflicting A/AAAA/ANAME/CNAME record, which tells the agent about uniqueness/conflict preconditions.

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?

Two short sentences, front-loaded with the action and followed by the failure condition. No wasted words and appropriately sized for the tool's complexity.

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-param create tool with a fully documented schema and mutation annotations, the description covers purpose and the conflict failure mode. Missing details like permission requirements or the return payload are minor since there is no output schema and annotations already convey the safety profile.

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 all four parameters (url, host, frame, domain_id) are already documented in the schema. The description adds no parameter-level detail beyond what the schema provides, so the baseline 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?

States a specific verb and resource ('Create a new HTTP forward for a domain'), which is distinct from the many create_dns_record/create_* siblings. It doesn't explicitly name a sibling to contrast against, but the resource ('HTTP forward') is unambiguous.

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 implied use case (adding a forward) is clear from the verb, and the precondition that the host must not already have a forward gives some context. However, no alternatives are named (e.g. update_forward, create_dns_record) and there is no explicit when-not guidance.

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