os_apps_render_ui_probe

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

Annotations declare readOnlyHint=true and idempotentHint=true, so the description does not need to restate safety. However, the description adds no behavioral context beyond the annotations: it does not explain what 'probe' returns, whether it renders a UI, or what side effects (if any) it has. With annotations covering the safety profile, a 3 is appropriate because the description adds minimal value but does not contradict 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?

The description is extremely short (one sentence), which is concise, but it is under-specified rather than efficiently informative. It front-loads the verb 'Probe' but the sentence does not earn its place because it lacks actionable detail. It is not verbose, but it is not a model of concise clarity.

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?

Given the tool has an output schema and three optional parameters, the description is incomplete. It does not explain the purpose of the parameters, what the output represents, or how this tool relates to the many sibling os_apps_render_* tools. The output schema may help, but the description alone leaves too much to inference for an agent to select and invoke this tool correctly.

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 description coverage is 0%, and the description provides no parameter information. The schema shows three optional parameters (tool, contentMode, resourceUri) with no descriptions, enums, or defaults. The description does not compensate for this gap, leaving an agent to guess what contentMode and resourceUri mean in the context of 'probing UI rendering support.'

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 'Probe MCP-Apps UI rendering support' is vague. It names a resource ('MCP-Apps UI rendering support') and a verb ('probe'), but does not specify what probing means, what the tool actually does, or what output it produces. It does not distinguish it from the many sibling os_apps_render_* tools, which all appear to render UI components.

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 is given on when to use this tool versus the sibling render tools (e.g., os_apps_render_boundary_explorer, os_apps_render_feature_inspector). The description does not state any conditions, prerequisites, or alternatives. An agent cannot tell whether this is a health check, a capability discovery tool, or a rendering tool.

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