get_top_activity

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

No annotations are provided, so the description carries the full burden. It clearly states the core behavior (returns the top activity) and implies a read-only operation, but it does not disclose potential failure modes, permission requirements, or what happens when no activity is on top. For a simple getter 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 two short sentences, with the core functionality front-loaded and no filler. The second sentence is arguably redundant with the schema, but it is brief and harmless.

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 simple tool with no parameters and no output schema, the description covers the essential purpose and return value. It does not describe the return format (e.g., a string or object), but the phrase 'returns the singular activity' gives enough context for an agent to infer a single activity identifier.

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?

With 0 parameters, the baseline is 4. The description reinforces the input contract by explicitly stating 'No parameters are required,' which adds a small confirmation beyond 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?

The description uses a specific verb ('returns') and resource ('the singular activity currently on top on the connected Android device'), and the qualifier 'singular' clearly distinguishes it from the sibling tool get_top_activities. An agent can understand exactly what this tool does without opening the 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?

The description implies when to use it by stating it returns the singular top activity, which contrasts with the plural sibling, but it does not explicitly say 'use this when you need only one activity' or mention alternatives. There is no exclusion or context for when to prefer this over get_top_activities.

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