cluster_add_host

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

The description labels the tool as '[WRITE]', which aligns with annotations (readOnlyHint=false). Beyond that, it adds minimal behavioral context: it describes the operation as 'move', which could imply existing host relocation, but does not clarify idempotency, side effects, or error conditions. Annotations already cover destructiveHint and openWorldHint, so the description adds only slight clarification.

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 very concise: two sentences plus a formatted argument list. It front-loads the action with '[WRITE]', then lists parameters in a clear, readable format. No extraneous information, every part serves a 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?

Given the tool's simplicity (3 parameters) and the presence of an output schema (which explains return values), the description is fairly complete. However, it lacks prerequisite information (e.g., host must be unassociated or cluster must exist) and error conditions. With annotations covering safety, it is adequate but not comprehensive.

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 has 0% description coverage, so the description must compensate. It provides brief descriptions for each parameter: 'Target cluster name', 'ESXi host name to move into the cluster', and 'Optional vCenter target name from config'. These add meaning beyond the field names but lack specificity (e.g., format, validation rules). The descriptions are helpful but minimal.

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 clearly states '[WRITE] Move a host into a cluster', specifying both the action and the resource. It distinguishes this tool from siblings like cluster_remove_host (removing a host) and cluster_create (creating a cluster), making its purpose 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 description implies usage for adding a host to a cluster but provides no explicit guidance on when to use it versus alternatives, prerequisites (e.g., host must be unassociated), or exclusions. Sibling tools like cluster_info or cluster_create are not referenced, so the agent must infer appropriate contexts.

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