List files in the config directory

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

While readOnlyHint already declares a safe read, the description adds real behavioral context beyond the annotations: the required ha:files scope and why it spans writes (credentials in these files), plus the exclusion that internal .storage is never listed. These are non-obvious constraints an agent would otherwise miss.

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?

Three tight sentences, front-loaded with what the tool does before the scope prerequisite and exclusion. The credentials rationale is slightly more than strictly needed but earns its place by explaining the unusual scope requirement.

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 no-output-schema listing tool, the description covers scope, the default path behavior, the auth prerequisite, and a notable exclusion. Return-format detail is unnecessary given no output schema, leaving little 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?

Schema coverage is 100%, so the schema already documents both path and instance_id fully. The description's 'omit path for the root' restates the schema's own hint rather than adding new meaning, so it sits at the baseline.

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?

States a specific verb (List) and resource (a directory under Home Assistant's config directory), with the scope 'under HA's config directory' making it distinct from generic config reads. It does not explicitly name the sibling read/write/delete config-file tools, but the listing scope is unambiguous.

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?

'Omit path for the root' gives default-behavior guidance, and the scope note functions as a prerequisite. However, it never states when to reach for this tool versus ha_read_config_file or ha_get_config, so the agent must infer the choice from the verb alone.

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