query_viewport_visibility

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

The readOnlyHint annotation already signals no writes, but the description adds context beyond that by clarifying it does not even read persisted entity enabled values. This explains that the operation is scoped to transient viewport state, which is useful behavior not present in the annotations.

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?

Two sentences with no filler. The primary action is front-loaded, and the clarifying scope constraint is provided immediately after. Every sentence 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 query tool, the description is complete: it states the exact result ('list entities hidden only in the editor viewport') and the safety profile is already covered by annotations. No output schema exists, but 'list entities' sufficiently conveys what the tool returns.

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 no parameters, so there is no parameter semantics burden on the description. The baseline of 4 applies because with zero parameters, nothing is missing or ambiguous about invocation inputs.

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 ('List') and a specific resource ('entities hidden only in the editor viewport'). The clarifying clause about not reading or changing persisted enabled values distinguishes it from operations dealing with persisted entity state, so an agent can tell this apart from sibling set/query tools.

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?

It implies usage for transient editor-viewport-only hidden entities and explicitly notes it does not read or change persisted enabled values, but it never names an alternative tool or states when to prefer this over siblings like query_viewport_state or set_viewport_visibility. The guidance is inferable rather than explicit.

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