scan_directory

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

The description is moderately transparent, indicating it's a 'cheap overview' implying lightweight execution, and that it provides one-line gists and labels. However, with no annotations, it fails to disclose important behavioral traits such as read-only nature, permission requirements, limits on large directories, or the exact meaning of 'code health and churn'.

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 concise at two sentences, with no extraneous content. However, it is front-loaded but sacrifices clarity on parameters and output. It is not as structured as it could be, failing to separate purpose from details.

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?

Given 9 parameters, no output schema, and no parameter descriptions in the schema, the description is grossly incomplete. It does not explain return value structure (e.g., format of tree, gists, labels) or how parameters affect behavior. The tool is non-trivial, lacking essential context for proper invocation.

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 has 9 parameters with zero descriptions (0% coverage), and the description does not explain any parameter beyond vague references to directory scanning. An agent cannot infer the meaning or usage of parameters like mode, delta, depth, pattern, max_files, output_format, exclude_patterns, or respect_gitignore from the description alone.

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 clearly states the tool scans directories producing a file tree with one-line gists and code health/churn labels, and distinguishes itself as a replacement for Glob/ls across all file types. However, it does not explicitly distinguish from siblings like list_directories or scan_file, lacking specificity on output format.

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 description implies usage as a 'good first call' and 'replaces Glob/ls', suggesting it's a starting point for directory overviews. However, it does not provide explicit when-to-use or when-not-to-use guidance compared to sibling tools such as scan_file or scan_diff.

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