List built-in card templates

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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world. The description adds genuine context beyond them: it reads a module-level constant and makes no Home Assistant call, signalling a fast, side-effect-free local read. It stops short of richer behavioral detail (e.g. ordering, caching), hence a 4 rather than 5.

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?

Three front-loaded sentences with clear Purpose / Use when / Returns structure and zero filler. The source constant is called out immediately, before the routing and return details.

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 simple filtered-list tool, the description covers source, usage routing, and returns. Annotations carry the safety profile and an output schema exists, so the return-shape mention is bonus rather than a gap.

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 sole `domain` filter is already fully documented by the schema. The description adds no additional syntax or semantics for it, 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 and resource (list built-in Card Builder recipe templates) and names the underlying source (`CARD_RECIPES`). It also distinguishes itself from the closely-named siblings by clarifying it makes no Home Assistant call, unlike most read tools in this namespace.

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?

Explicitly names the workflow: browse here, then preview with `card_builder_get_card_template` or instantiate with `card_builder_make_template_card`. This routes the agent to the correct sibling at each subsequent step, leaving nothing to inference.

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