ha_file_exists

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

With no annotations provided, the description carries full burden for behavioral disclosure. It only states the basic purpose and does not mention return type (e.g., boolean), error behavior, or that it is a read-only operation. This leaves the agent uncertain about outcomes.

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 front-loads the purpose. It contains no redundant information, though it could be slightly improved by adding a note about return type without sacrificing brevity.

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 existence check, the description minimally covers the tool's purpose. However, it does not specify the output format or handle edge cases. Given no output schema, the description should clarify what the tool returns, which 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 sole parameter 'path' has complete schema description (100% coverage) including an example. The tool description does not add further meaning beyond the schema, so baseline score of 3 is appropriate.

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 specifies the verb (check), resource (file/directory), and context (Home Assistant server, path relative to /config/). It effectively distinguishes from sibling tools like ha_read_file or ha_delete_file by focusing solely on existence check.

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?

Usage is implied by the tool's name and description, but no explicit guidance is given on when to use this tool over alternatives like ha_list_files or ha_read_file. The description lacks 'when to use' or 'when not to use' statements.

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