List devices

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

Annotations already declare readOnlyHint=true, so the tool's read-only nature is covered. The description adds that it returns 'current state', which is somewhat behavioral, but it does not mention caching, data freshness, or any other runtime characteristics. Given the annotation coverage, the description adds modest value beyond it.

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 sentence, front-loaded with the action and resource, followed by a brief and clear note about parameters. There is zero fluff and every word earns its place.

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?

This is a simple tool with no parameters, an existing output schema, and annotations covering its safety profile. The description states the two key return categories (devices and routines), which is sufficient for an agent to invoke it correctly. No critical information 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 input schema has zero parameters, so baseline 4 applies. The description's 'Needs nothing' reinforces the empty schema but does not add any new parameter-related meaning beyond what is already structurally obvious. This is slightly helpful but not essential.

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 states the tool 'lists' smart-home devices with their current state and the routines that can be run, which is specific and distinct from sibling tools like set_device_state or run_routine. The 'Needs nothing' note also clarifies parameterlessness, making the purpose 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?

The description implies usage for retrieving device and routine information, but it does not explicitly state when to use this tool over alternatives such as get_household_summary or list_chores. No exclusions or conditions are provided, so the guidance is only implied.

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