List theme files on disk

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds non-annotation behavior: recursive scan under `<config>/themes/`, path relativity, and the empty-list result when the directory is absent.

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?

Front-loaded purpose sentence, then scope, then usage, then return. Slightly redundant: the return format ('paths relative to the config directory') is stated twice, which is wasted given an output schema already exists.

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?

Zero parameters, full annotation coverage, and an output schema means little is required of the description. It still covers scope, edge case (missing directory), and when to prefer this over the sibling list tool, so nothing an agent needs is missing.

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, so per the baseline this is scored 4. The schema is empty and additionalProperties=false, and the description correctly implies no filtering arguments exist.

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 ('List YAML theme files present on disk under themes/') and pins down the scan location and file types. Combined with the title and the sibling themes_list_themes, an agent can immediately tell this reads the filesystem rather than the loaded theme registry.

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?

The 'Use when' line gives an explicit triggering condition and names the alternative tool ('a theme exists on disk but isn't showing up in themes_list_themes'). It lacks an explicit when-not-to-use clause, which is the only thing keeping it from a 5.

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