ha_call_service

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

No annotations are provided, so the description must fully disclose behavior. It fails to mention side effects, permission requirements, synchronicity, or error handling. For a tool that triggers real-world actions, this is a significant gap.

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 concise at two sentences, front-loading the purpose and then providing examples and a usage hint. It is efficient but could be slightly more structured.

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 complexity (general service caller with 4 parameters, no output schema, no annotations), the description is too minimal. It lacks guidance on the domain/service pattern, optionality of entity_id, and the nature of the response, making it incomplete for an agent to use confidently.

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 explain parameters. It only addresses the 'data' parameter with a note about extra params. The other parameters (domain, service, entity_id) are not explained, leaving ambiguity despite the examples.

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 'Call any Home Assistant service' and provides specific examples (light.turn_on, climate.set_temperature), which distinguishes it from sibling tools that are all read/get operations.

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 context of use is implied: use when you want to perform an action rather than read. The sibling tools are all query/read functions, so the description's action-oriented purpose provides clear separation. However, it does not explicitly state when not to use it or list alternatives.

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