list_themes

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

With no annotations, the description carries the full behavioral burden and does well: it discloses the exact count (24), the family/parent/pinned-sibling structure, the terminal exception, and the selector behavior of emitted CSS. It stops short of describing return shape (strings vs. objects) or whether paths are included, which is the remaining gap.

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?

The purpose is front-loaded and clear, but the bulk of the text is a 24-item name dump followed by implementation minutiae about light-dark() and :root selectors. The names are plausibly useful, yet the CSS mechanism detail reads as tangential to a discovery/list tool and inflates the description.

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 zero-parameter tool with no output schema, the description does the heavy lifting by explaining the theme catalog and its grouping, which is what an agent needs to call the right follow-up tool. It omits any statement of return format or whether theme file paths are exposed, leaving a small gap.

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 and the schema is empty, so there is nothing for the description to clarify; per the baseline this scores 4.

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 opens with a specific verb+resource ('List all 24 shipped themes') and even enumerates the resource set, so the agent knows exactly what the tool returns. It does not name siblings like get_theme or search_themes to differentiate itself, but the enumerative framing makes the distinction obvious without opening any 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?

Usage is implied rather than stated: the enumeration of all themes suggests 'use this to discover what exists', and the note about data-theme sharing hints at bundle scenarios. There is no explicit 'use get_theme to fetch one' or 'use search_themes to filter', so the agent must infer the routing.

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