Get Shield status

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

Annotations already declare readOnlyHint=true, so safety is covered. The description adds genuinely non-obvious behavior: stale=true signaling unreachable state, that power/app/volume are last-known values with as_of timestamping, and that error explains why. The dry_run note is somewhat tangential for a zero-parameter read tool but still adds context.

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?

Front-loads the key orientation phrase "Start here" and stays compact across two short paragraphs. The final dry_run sentence is loosely related to a no-param read tool and slightly dilutes focus.

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?

An output schema exists, so return values need not be restated, and the description still covers the ambiguity the schema cannot express: stale-value semantics, timestamp/error fields, and the distinction from get_now_playing. Nothing needed to call it correctly 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 tool takes zero parameters, so the baseline is 4. There are no parameter semantics to clarify, and nothing in the description misrepresents the empty schema.

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 (get Shield status) and enumerates exactly what is returned: reachability, power state, foreground app, and volume. It also distinguishes itself from the sibling get_now_playing, so an agent can separate the two without opening schemas.

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?

"Start here" gives explicit entry-point guidance, and the description names the boundary condition and alternative: it does not report what is playing, while get_now_playing does (if ADB is set up). That is an explicit when-to-use plus a when-to-use-instead.

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