Select an input_select option

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

Annotations already declare idempotent=true, destructive=false, and not readOnly, so safety is covered. The description adds value by revealing the concrete RPC (input_select.select_option with the entity_id/option payload) and that it returns the list of states changed, which is beyond the structured fields.

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 with the core purpose, then use-when/not-for/returns in tight labeled clauses. The HTTP payload detail is slightly redundant given the schema but does not bloat the description.

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 two-param, idempotent helper setter, the description covers purpose, routing to the sibling, and return behavior, and an output schema exists so return values need no further explanation. Nothing required to call it correctly 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?

Schema coverage is 100% and both parameters are self-documented, so the schema carries the load. The description only restates the payload mapping (entity_id, option) without adding format or constraint detail beyond the schema, matching the baseline for high coverage.

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: setting an input_select helper to one of its configured options. It also names the underlying service call and clearly delimits itself from the generic sibling, so an agent can distinguish it without opening a 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?

Explicit 'Use when' for setting a known input_select to a specific option, and 'Not for' pointing to entities_select_option for the generic select/input_select dispatch. Both the selection condition and the alternative are named.

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