Validate ESPHome config

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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds real operational context: it runs over the VomeHome relay with no ports to open, and it tells the agent how to handle an unreachable instance rather than misreporting. Return summarization behavior is useful but partially overlaps the schema.

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 tightly packed sentences, front-loaded with the core action and then the practical guidance. Every sentence earns its place and none restate the title.

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 non-destructive validate tool with full annotation and schema coverage, the description covers purpose, the pre-compile workflow position, and error remediation. Nothing an agent needs to invoke it correctly is missing, and no output schema is required since the return is 'the output'.

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 description coverage is 100%, so all four parameters (full_output, instance_id, configuration, timeout_seconds) are already documented in the schema, setting the baseline at 3. The description references 'return the output' but adds no syntax or format detail beyond what the schema provides.

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+resource ('Validate (compile-check) an ESPHome configuration') and immediately frames its scope relative to siblings by saying it's the step before compiling or flashing. An agent can distinguish it from esphome_compile and esphome_upload without opening any schema.

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?

Explicitly says when to use it ('the fast way to confirm a YAML edit is correct before compiling or flashing'), which implies the alternative (full compile/upload) and the condition selecting this tool. It also routes the agent on failure: use esphome_dashboard_info if ESPHome is unreachable, rather than reporting it unsupported.

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