app_get_error

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

The description adds 'Read-only', which aligns with the readOnlyHint annotation. It also explains that the result is a human-readable string obtained over BLE, providing additional context beyond the annotation.

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 two sentences long, front-loaded with the tool's purpose, and contains no superfluous words. Every sentence adds value.

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 tool with no parameters and a clear read-only purpose, the description is sufficiently complete. It mentions the output is a human-readable string, which is adequate given that an output schema exists (though not shown). Could be slightly more precise about error formats, but not necessary.

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, and schema description coverage is 100% (trivial). According to guidelines, 0 params = baseline 4. The description does not need to add parameter info since there are none.

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 reads the last error as a human-readable string over BLE. It uses specific verb 'read' and resource 'running app's last error'. It distinguishes from sibling tools that return status codes, like app_launch, app_button, and transmit.

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 explicitly says 'Call this when an app_launch / app_button / transmit returns a bare status code, to get the app's own error text.' This provides clear context for when to use the tool, though it lacks explicit when-not or alternative recommendations.

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