Set UI theme

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

Annotations only declare readOnlyHint=false and openWorldHint=false. The description adds real value by disclosing that changes persist to SaveData.Custom and that a return 'apply snippet' is produced, which tells the agent about side effects and output beyond the 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 front-loaded sentences with no filler, opening on the verb and resource before listing the parameter groups. The parameter dump is dense but tightly sized for a 10-parameter tool.

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?

A 10-parameter mutation tool with no output schema and only 30% schema coverage. Persistence and return behavior are covered, but the meaning of most numeric modes and color parameters is absent, leaving the agent under-informed for full invocation.

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 only 30%, so the description must compensate. It restates parameter names and the AccentMode/HarmonyMode ranges that the schema already provides, but leaves TriColorMode, IntroColorMode, ColorSat/Speed/Bright, and IntroColor unexplained in either place.

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 ('Change UI theme') and names the parameter families involved. It does not explicitly distinguish itself from close siblings like reanim_apply_theme_preset or reanim_set_customization, so it is clear but not fully differentiated.

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?

No when-to-use guidance and no mention of alternatives, despite obvious candidates such as reanim_apply_theme_preset or reanim_set_customization. The agent gets no condition that selects this tool over its siblings.

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