Set a named starting point for a prototype flow by marking a frame as its entrypoint, enabling clear organization and testing of specific user journeys.
Mark a screen frame as a named prototype flow starting point (e.g. 'Onboarding Flow', 'Purchase Flow')
| Name | Required | Description | Default |
|---|---|---|---|
| name | Yes | User-facing name of the prototype flow | |
| nodeId | Yes | Frame node ID to designate as entrypoint |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden of behavioral disclosure. 'Mark' is vague: it does not say whether this mutates the frame, persists a named flow, overrides an existing starting point, or requires a specific frame type. These side effects are left entirely unstated.
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 a single sentence with no filler. It front-loads the core operation ('Mark a screen frame'), then specifies the resulting state ('named prototype flow starting point') and relevant examples.
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?
This is a simple two-parameter tool with a complete input schema, so the description is minimally viable. However, without annotations or an output schema, it leaves behavioral and routing context unexplained, especially the relationship between a flow starting point and the broader prototype interaction workflow.
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 100%, and both parameters already have clear descriptions in the schema. The tool description adds illustrative examples of flow names but no additional syntax, constraints, or edge-case meaning beyond what the schema provides.
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 and resource: 'Mark a screen frame as a named prototype flow starting point'. It clearly says what the tool does and gives concrete examples ('Onboarding Flow', 'Purchase Flow'), but it does not explicitly contrast itself with sibling tools like set_prototype_interaction.
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 phrase 'prototype flow starting point' and the examples imply when this tool applies, but the description never states when to use it instead of related tools such as set_prototype_interaction or batch_link_prototype, nor does it mention any exclusions or prerequisites.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.