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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered; the description reinforces this with 'Does NOT change the site' and adds the two-step workflow context (choice applied later via set_theme). It does not disclose anything about the interactive/UI nature of the call or what the tool returns to the agent.

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 short sentences with zero filler, and the most important constraint (does not change the site) is front-loaded alongside the routing hint.

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, single-parameter tool with a fully documented schema and no output schema, the description covers purpose, non-mutation, and the follow-up action. Only the nature of the user-facing interaction is left implicit.

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% and the single parameter's nested structure (name, description, 12-color palette) is fully documented in the schema itself. The description adds no format or content guidance beyond the schema, 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 (show palette options for the user to pick), and explicitly distinguishes itself from the mutation path by naming set_theme. It is slightly ambiguous whether the tool generates the palettes or merely presents the options supplied in the input, but the core action is clear.

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?

Gives a clear usage condition — this is the presentation/selection step, not the application step — and names the alternative sibling (set_theme) that performs the actual change. No explicit exclusions beyond that, but the when-to-use is unambiguous.

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