Get HA Core info

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

Annotations already declare readOnly/idempotent/non-destructive, so the bar is lower, yet the description still adds genuine context: the underlying endpoint, the specific error payload returned when SUPERVISOR_TOKEN is missing, and the requirement that Nexus run as an HA add-on. No behavioral trait beyond that (e.g. rate limits) is disclosed, but this is solid added value.

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?

Front-loaded and clearly partitioned into Use when / Not for / Returns / Errors. Slightly redundant in that the endpoint line and the Returns line both restate version/arch/machine, which duplicates what the output schema already carries, but every block is otherwise useful.

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?

All call-relevant facts are present: the endpoint, the auth prerequisite and its failure mode, and differentiation from siblings. The return-value detail is redundant given the output schema but harmless, so nothing an agent needs is missing.

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 tool takes zero parameters, so per the rubric the baseline is 4. There is no parameter surface for the description to clarify, and it correctly does not invent any.

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 and resource (get info about the Home Assistant Core container) and names the exact endpoint and fields returned (version, CPU architecture, machine type). It explicitly distinguishes itself from the Supervisor and host info siblings, so an agent can route correctly without opening the schema.

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?

Contains explicit 'Use when' (checking Core version/arch vs Supervisor or host) and 'Not for' clauses that name the alternative tool (`history_get_ha_config`) for HA's own config. When-to-use, when-not-to-use, and the alternative are all stated.

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