ecp_files_is_directory_exists

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

The description conveys the core behavior—checking existence—and implies a read-only operation, but it does not explicitly state whether it returns a boolean, raises errors for missing paths, or requires permissions. With no annotations to fill this gap, the behavioral picture is adequate but minimal.

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 front-loaded sentence that states the operation with no wasted words. It is appropriately sized for a simple predicate tool.

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 one-parameter existence check, the description is minimally viable. However, with no output schema and no annotations, it leaves the return format and path semantics unstated, so the agent must rely on inference and naming conventions.

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 only parameter, 'directory', is self-describing by name, but the description adds no guidance on expected format (absolute vs. relative path), symlink behavior, or whether the directory must be accessible. At 0% schema description coverage, the description needed to compensate and did not.

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 verb ('Check') and a specific resource ('a directory'), and the tool name narrows it to existence testing. This clearly sets it apart from sibling file tools like ecp_files_list, ecp_files_directory_tree, and ecp_files_read.

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 provides no guidance on when to use this tool versus alternatives, such as before creating or accessing a directory. It names no exclusions, preconditions, or sibling tools that might be more appropriate for related tasks.

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