Skip to main content
Glama

opointo

by com.opointo
OverviewDiscussionsAdmin

Add a screen to an app

add_screen
Read-onlyIdempotent

Needs a subscription. Adds one screen designed in the Designer to a project. With the project's .opointo/files.json it returns the screen file, the route that mounts it and the one line to register it, and never rewrites existing files. Without it, a self-contained screen file for any Expo app.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
tabNonest it in this tab's stack; omit to place it where the design does
appIdYesthe share code from "Send app to agent"
screenNothe new screen's name in that design
manifestNothe parsed .opointo/files.json
componentNameNoonly to add a second copy of a screen; omit for the export's name

Schema Changelog

Changes observed during successful MCP inspections.

  1. Changed2 schema fields changed
    • changedInput schema / properties / componentName / description
      Previous value: -"e.g. \"InvoiceScreen\""New value: +"only to add a second copy of a screen; omit for the export's name"
    • changedInput schema / properties / tab / description
      Previous value: -"nest it in this tab's stack; omit for the root, which covers the tab bar"New value: +"nest it in this tab's stack; omit to place it where the design does"
  2. Changed7 schema fields changed
    • addedInput schema / properties / appId
      Added value: +{
+  "description": "the share code from \"Send app to agent\"",
+  "type": "string"
+}
    • changedInput schema / properties / componentName / description
      Previous value: -"React component name, e.g. \"InvoiceDetail\". Defaults to GeneratedScreen."New value: +"e.g. \"InvoiceScreen\""
    • removedInput schema / properties / compositionId
      Removed value: -{
-  "description": "share code for the new screen, from the App Builder",
-  "type": "string"
-}
    • changedInput schema / properties / manifest / description
      Previous value: -"the parsed .opointo/files.json from the project root"New value: +"the parsed .opointo/files.json"
    • addedInput schema / properties / screen
      Added value: +{
+  "description": "the new screen's name in that design",
+  "type": "string"
+}
    • changedInput schema / properties / tab / description
      Previous value: -"nest it in this tab's stack so the tab bar stays visible. Omit to put it at the root, where it covers the tab bar (right for a modal)."New value: +"nest it in this tab's stack; omit for the root, which covers the tab bar"
    • changedInput schema / required
      Previous value: -[
-  "compositionId",
-  "manifest"
-]New value: +[
+  "appId"
+]
  3. First observed

TDQS

A3.7/5.0
Behavior4/5

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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety bar is lower; the description still adds real context beyond them: the subscription requirement, the guarantee that existing files are never rewritten, and what the call yields (screen file, mounting route, registration line). The opening 'Adds ... to a project' sits in mild tension with readOnlyHint, though the same sentence's 'returns the screen file ... never rewrites existing files' resolves it in favor of the read-only annotation.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Three tight sentences with the prerequisite front-loaded and no filler. The middle sentence is slightly run-on, packing return values and the no-rewrite guarantee together, but the whole entry is appropriately sized.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description correctly covers the return surface (screen file, route, registration line) and states the subscription prerequisite plus the non-destructive guarantee. Remaining gap is the absence of any routing to sibling tools (e.g. propose_screen), which matters given the crowded sibling set.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema already documents all five parameters (tab, appId, screen, manifest, componentName). The description adds only indirect meaning, tying the presence of manifest to a different return shape, so the baseline 3 for full schema coverage applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource: it adds one Designer-authored screen to a project and specifies the two operating modes (with vs without the project's .opointo/files.json). It does not, however, differentiate itself from siblings such as propose_screen or emit_app, which an agent must otherwise infer.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives a prerequisite ('Needs a subscription') and the condition that selects each behavior mode (manifest present vs absent), which is genuine usage guidance. It never names an alternative tool or states when not to use this one, so the when-to-use-vs-siblings question is left to inference.

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

All opointo toolsInspect
Try in Browser
Shareable, User-Owned Context BackendPeople, applications, and agents read, write, and coordinate together in one context lake. Reach it over MCP, a CLI, a Python SDK, or REST.fulcradynamics.comAd

Glama MCP Gateway

Add one secure layer between your agents and this server.

Resources