List effects

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

Annotations already mark readOnlyHint=true. The description adds useful behavioral nuance: 'Some firmware cannot report a numeric id for the current effect, in which case only currentEffectUniqueId is set.' No contradictions with annotations.

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?

Two sentences, front-loaded with purpose, a critical firmware caveat, and a pointer to set_effect. Every word earns its place; no fluff.

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 read-only list tool with one optional param, an output schema, and annotations, the description covers purpose, output contents (count/ids/current), a firmware limitation, and an alternative action. It is complete.

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 schema provides 100% coverage for the only parameter (optional 'device' with description). The tool description adds no additional parameter semantics, so the baseline of 3 is appropriate.

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?

The description states a specific action: 'List the predefined effects available on a Twinkly device (count + unique ids) and which effect is currently selected.' It clearly distinguishes from siblings like list_movies (effects vs movies) and set_effect (list vs play).

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?

Clear context is provided: listing effects and current selection. Explicitly mentions 'Use set_effect with an effect id to play one,' pointing to an alternative. However, no when-not-to-use exclusion is stated, so it falls short of a full 5.

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