Skills, commands and subagents the repo ships

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

With no annotations, the description carries the transparency burden and does well by disclosing key behaviors: it searches root or one/two levels down, counts distinct extensions and markdown files, and explicitly states 'contents are never returned.' It omits details like output format or error behavior, but the essential behavioral facts are present.

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 description is three sentences with useful scoping details, though the first sentence is long and packs the action verb later in the paragraph ('Counts...'). There is minimal redundancy, but it could be slightly more front-loaded, so it earns a 4 rather than a 5.

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?

Although there is no output schema, the description compensates by stating what is returned (counts, names, and sizes) and where it looks. It does not address edge cases like a missing directory or symlink behavior, but for a simple read-only inspection tool the essential context is covered.

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 input schema already fully documents the single optional `dir` parameter with 100% coverage, including its default behavior. The description adds no parameter-specific meaning beyond what the schema provides, so the baseline score of 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?

The description uses a specific action ('Counts distinct extensions and the markdown files they carry') and clearly identifies the resource (`.claude/` or `.agents/` directories). It also distinguishes itself from sibling tools by scoping to skills, slash commands, subagents, and plugin markers, and explicitly states the output limitation ('Names and sizes only').

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?

Provides clear context on when to use the tool: it inspects agent extensions shipped in the checkout and handles monorepo layouts ('one to two levels down'). However, it never explicitly contrasts with sibling tools like instruction_files or declared_mcp_servers, nor states when not to use it.

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