set_viewport_realtime

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

Annotations already declare the mutation profile (readOnly=false, destructive=true, idempotent=true), so the bar is lower. The description goes further by surfacing the return shape, which reveals non-obvious override semantics (effective_realtime vs realtime, override_active, override_source) that the agent wouldn't otherwise expect from a simple toggle.

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?

One-sentence purpose is front-loaded and the returns block is compact. Both parts earn their place, though the redundant 'requested/realtime/effective_realtime' trio is slightly verbose.

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 single-parameter toggle with no output schema, the description covers both the action and the response, which is the main completeness gap. It stops short of explaining what an override is or why effective_realtime can differ from the request.

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?

Schema coverage is 100% and the single 'enabled' boolean is documented in the schema itself ('True to turn on realtime updates, false to turn them off'). The description adds nothing beyond that, so baseline 3 applies.

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 action (enable/disable), resource (realtime rendering), and scope (active editor viewport). An agent can distinguish it from sibling viewport tools like set_viewport_view_mode or get_viewport_state, though it doesn't name any sibling explicitly.

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?

No guidance on when to use this versus alternatives such as set_viewport_view_mode, set_game_view, or the get_viewport_* readers. The scoping to the 'active editor viewport' implies where it applies but not when an agent should reach for it.

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