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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds real domain context beyond that: variants are whole palettes 'kept alongside the applied one', which tells the agent that listing does not disturb the currently applied palette and that variants are parallel alternatives rather than sequential states.

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?

One front-loaded sentence with no boilerplate; the em-dash apposition and ellipsis convey the sidebar naming convention compactly. Slightly conversational, but nothing is padding.

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?

No output schema exists, and the description does enough to let an agent interpret results: it explains that variants are named 'Variant 1, Variant 2 …' in the sidebar and that each is a full palette. It is complete for a simple single-parameter read, though it never says what fields come back (ids vs names).

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?

There is only one parameter (projectId) and schema description coverage is 0%. The phrase 'on this project' implies projectId scopes the listing, but no format, ID source, or lookup hint is given. Baseline 3 for a single-parameter tool whose schema is undocumented in both places.

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 resource (the colour variants / whole palettes on a project) and clarifies what a variant actually is, so an agent knows this is a read of existing alternatives rather than palettes themselves. The verb is only implied ('this is how you see what alternatives a project already has'), and no sibling is named explicitly, so it stops short of a 5.

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?

'...before adding another' gives a clear triggering context: check existing variants prior to calling create_variant. There is no exclusion list or explicit naming of the alternative tool, but the when-to-use is unambiguous for this tool's main decision point.

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