List Card Builder cards

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

Annotations already declare readOnlyHint/idempotentHint/destructiveHint=false, so the safety profile is covered. The description adds genuine context beyond that: it identifies the underlying WebSocket command and notes the result is unfiltered and in storage order, which tells the agent what to expect from the collection.

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 action, then labeled 'Use when:' and 'Returns:' sections, which is easy to scan. The enumeration of every returned field is slightly redundant given a full output schema exists, making it a touch longer than strictly necessary.

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 zero-parameter, read-only list tool with an output schema already present, the description supplies everything the agent needs: scope, the routing alternatives, and the nature of the returned collection. Nothing required to invoke 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?

The tool takes zero parameters, which is the baseline case for a 4. The description correctly implies no filtering or pagination arguments are available ('unfiltered'), aligning with the empty schema.

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 every Card Builder card') scoped to 'this Home Assistant instance', and names the underlying WebSocket command. The sibling tools card_builder_get_card and card_builder_update_card are referenced so an agent can distinguish listing from reading or editing.

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 'Use when:' clause gives explicit context (discovering existing cards) and names the two alternative tools for follow-up actions. It lacks an explicit 'when not to use' or a note about why no filtering alternative exists, so it is clear but not fully exhaustive.

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