Switch active VomeHome instance

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

Annotations only say readOnlyHint=false and openWorldHint=true; the description goes far beyond by disclosing the permission model: write/config permission follows the target instance's own flags, flags come from VOMEHOME_INSTANCES or the default, are auto-granted on create, an undeclared-but-reachable instance inherits the global default, and brokered mode defers to the API key's server-side scopes. That is exactly the non-obvious operational context an agent needs.

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 core action is front-loaded in the first clause and the text is a single dense sentence with no filler. It is somewhat run-on and information-heavy for one sentence, but every clause carries real content rather than restating the name.

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-parameter switch, the definition covers purpose, downstream effect, and the full permission-inheritance model. It does not cover the return shape or whether the switch persists across sessions, but with no output schema and openWorldHint already declared, the remaining gap is minor.

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 the single instance_id parameter is already documented, including that it comes from vomehome_list_instances. The description adds no syntax, format, or validation detail for the parameter itself, 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 (switch) and resource (active VomeHome instance) and immediately scopes its effect: subsequent ha_* calls target this instance. This clearly separates it from vomehome_list_instances and vomehome_get_instance, which read rather than mutate the active target.

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 establishes the usage context well — call it when you want later ha_* calls (states, services, automations, templates, check_config) to hit a different instance — and the schema points to vomehome_list_instances for obtaining the id. It stops short of explicit when-not guidance or naming an alternative switching route, so it is clear context without exclusions.

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