ha_call_service

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

With no annotations, the description bears full responsibility for behavioral disclosure. It only states 'Call' without revealing side effects, permissions, return values, or error behavior. This is a significant transparency gap for an action that can trigger arbitrary home assistant services.

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, front-loaded sentence with no wasted words. Every term ('domain', 'service', 'data payload') directly maps to parameters, making it efficient.

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 generic service-call tool with no output schema and no annotations, the description is too sparse. It omits that data keys are service-specific, that calling a service may have side effects, and that it can be used for custom services not exposed as dedicated tools. Incomplete for safe and correct invocation.

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 compensate. It mentions 'data payload' for the data parameter, but domain and service are only named, not explained. No examples, value formats, or constraints beyond the schema are provided.

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 specifies a clear action ('Call'), a resource ('Home Assistant service'), and the primary inputs ('domain/service' and 'data payload'). It is implicitly distinguished from sibling tools like ha_light_turn_on by being generic, but it does not explicitly name alternatives.

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?

No guidance is given on when to use this tool versus specific service tools or other siblings. It doesn't mention conditions, prerequisites, or exclusions, leaving the agent without context for selection.

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