get_directory_size

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

With no annotations, the description must disclose behavioral traits but only adds 'recursively', which indicates traversal behavior. It does not mention potential performance cost on large directories, symlink handling, or return value format, leaving significant behavioral ambiguity.

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 a single, concise sentence that immediately conveys the core functionality with no wasted words, perfectly front-loaded.

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 simple one-parameter tool, the description is adequately complete on purpose, but lacks return value details and performance caveats. Given no output schema, the description should clarify what the tool returns, which it does not.

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 schema already describes 'path' as a directory path, so the description adds minimal semantic value beyond the schema. Baseline 3 applies because schema coverage is 100% and the single parameter is self-explanatory.

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 'Get directory size recursively' clearly states the action (get size), the resource (directory), and the scope (recursively), distinguishing it from sibling tools that handle file reading, writing, and listing without any size-related functionality.

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 through its explicit 'recursively' qualifier, but does not provide explicit when-to-use guidance or mention alternatives. Since no sibling tool computes directory size, the intended context is inferred rather than directly stated.

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