Get Card Builder recipe guide

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description still adds real value by disclosing that it returns a static constant and makes no call to Home Assistant, which is behavior the annotations cannot convey.

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 structured with clear Use when / Not for / Returns labels, which is easy to scan. There is mild redundancy between the opening sentence, the 'Returns' list, and the 'Use when' content, but nothing that obscures the point.

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 parameterless guide-fetch tool with an output schema present, the description is fully sufficient: it explains what is returned, when to reach for it, and what to use instead. Nothing an agent needs in order 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?

The tool takes zero parameters, so there are no parameter semantics to explain and the baseline of 4 applies. The description correctly adds nothing spurious about inputs.

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 ('Get') and resource (the embedded recipe guide) and immediately scopes it as building 'Card Builder cards programmatically'. It explicitly distinguishes itself from the sibling `card_builder_design_principles`, so an agent can tell the two apart without opening either 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?

Provides an explicit 'Use when' clause (starting a card build, needing DocumentData shape, prop-wrapping, slots, recipe shorthand) and an explicit 'Not for' clause routing UX work to `card_builder_design_principles`. It even names the downstream tool, `card_builder_build_from_recipe`, that consumes its output.

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