is_overlay_visible

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

No annotations are provided, but the phrasing 'Returns whether...' clearly signals a non-mutating read query, which is the key behavioral trait. It does not clarify what counts as 'visible' (e.g., occlusion, transparency) or the freshness of the result.

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?

A single, front-loaded sentence with no filler. 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 boolean query with no output schema and no annotations, the description is nearly sufficient — it states the return meaning. A brief note on what 'visible' means or on related tools would make it complete.

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 schema baseline is 4. There are no parameter semantics for the description to add or omit.

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 (returns) and resource (whether the Portal overlay is visible), so the agent knows exactly what question it answers. It does not distinguish itself from siblings like get_screen_state or get_element_tree, which could also reveal overlay state.

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?

There is no guidance on when to call this versus alternatives such as get_screen_state, nor any preconditions. The agent must infer usage entirely from the name and description.

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