get_battery_level

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

No annotations are provided, so the description carries the burden of behavioral disclosure. It states that no parameters are required, which is useful. However, it doesn't disclose what the return value looks like (e.g., percentage, integer, string), whether it might fail (e.g., no device connected), or any side effects. For a simple read-only query, this is adequate but not rich.

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 that states the purpose and parameter requirement with zero waste. It is front-loaded with the action and resource, and the parameter note is concise. 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?

For a zero-parameter read-only tool, the description is mostly complete. The main missing piece is the return format (e.g., percentage vs. raw level), which an agent might need to interpret the result. However, given the simplicity of the tool and the absence of an output schema, the description provides sufficient context for calling it correctly, though not for fully understanding the response.

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 tool has zero parameters, and the schema confirms this with an empty properties object. The description explicitly states 'No parameters are required,' which adds clarity beyond the schema by confirming the agent doesn't need to supply anything. With 0 params, the baseline is 4, and the description meets it.

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's function: returning the battery level of a connected Android device. It uses a specific verb ('Returns') and resource ('battery level'), which is unambiguous. It doesn't explicitly differentiate from siblings, but no sibling appears to perform a similar function, so this is acceptable.

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 context: it's for querying the battery level of a connected Android device. It doesn't explicitly state when to use it versus alternatives, but given the sibling list, no alternative tool serves this purpose. The lack of explicit exclusions is a minor gap, but the context is clear enough for an agent to select it appropriately.

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