update_forward

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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description adds two useful pieces of context: that this is a 'preview' (produces a plan rather than applying) and that 'Host cannot be renamed'. It does not, however, explain what the preview returns or how it relates to apply_plan.

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 immediately followed by the key constraint. No filler, though it could still fit one more clarifying clause without bloat.

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?

An output schema is present so return values needn't be re-described, but for a tool wrapping a nested Forward object with 0% schema coverage the description is thin: it covers only the host constraint and omits the meaning of domain, url, and frame, leaving an agent needing the schema plus guesswork.

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 0%, so the description must carry parameter meaning. It only addresses the host field (via 'forward.host' and the no-rename rule) and leaves 'domain', the forward 'url', and 'frame' completely unexplained.

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 ('Preview updating') and resource ('the existing forward'), and identifies which field ('forward.host') is being addressed. It distinguishes itself from create_forward/delete_forward siblings, though 'forward.host' is slightly awkward notation.

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 word 'Preview' implies this is the non-mutating first step of a plan/apply flow, which matches the apply_plan/get_plan siblings, but the description never names an alternative or states an explicit when-to-use condition. Usage is only implied.

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