domain_update

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

With no annotations provided, the description carries the full burden. The 'WRITE:' prefix signals mutation, and 'Only the given fields change' discloses partial-update semantics rather than full replacement. However, it does not mention permissions, side effects, timing, or the fact that changing transfer lock or renewal mode may have irreversible or externally visible consequences. Some important behavioral context is missing.

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 a single dense sentence that covers the operation type, the resource, the modifiable fields, and the partial-update behavior with no filler. Every phrase adds information, and the 'WRITE:' prefix is an efficient way to convey mutation intent.

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?

This is a nine-parameter write operation with no annotations, no output schema, and minimal schema descriptions. The description only sketches the domain and fields, leaving out the required 'domain' parameter context, the meaning of integer contact fields, the purpose of 'testing', and any expected response or error behavior. This is insufficient for correct invocation without additional lookup.

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 only 11%, so the description must compensate, but it only groups parameters into categories ('nameservers', 'transfer lock', 'renewal mode', 'contacts'). It does not explain that tech/admin/billing/registrant are likely contact IDs, what the 'testing' flag does, or how renewalMode enum values map to behavior. The mapping from description to the nine parameters is incomplete and leaves the agent uncertain about several fields.

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 opens with a clear 'WRITE:' marker and states a specific action: changing nameservers, transfer lock, renewal mode, or contacts of an existing domain. This distinguishes it from siblings like domain_transfer and domain_renew, which perform different lifecycle actions. The phrase 'domain already at INWX' further scopes the operation.

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 clearly indicates this applies to an existing INWX domain, implying it is not for transfer, renewal, or availability checks. It does not explicitly name alternatives, but given sibling tool names the intended use case is inferable. The partial-update caveat 'Only the given fields change' gives practical guidance on how to use the tool.

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