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Glama

list_controls

List all inputs and outputs in a running Shiny app, including type, label, value, choices, and visibility. Re-run after dynamic UI changes to re-scan the page and see current controls.

Instructions

List every input (id, type, label, current value, choices, visible) and output (id, type, status, visible). Call again after dynamic UI changes: the page is re-scanned every time.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
app_idYes

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv0.1.0

TDQS

A4.1/5.0
Behavior4/5

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

With no annotations, the description carries the burden of behavioral disclosure. It reveals that 'the page is re-scanned every time,' indicating the tool returns a fresh snapshot and that repeated calls reflect dynamic UI changes. It does not mention side effects or permissions, but the listed fields and re-scan behavior give useful transparency for a list operation.

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

Conciseness5/5

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

Two tightly written sentences with no filler. The core purpose is front-loaded, the field list is compact, and the re-scan behavior is delivered in a second short sentence.

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?

The description enumerates the fields returned for inputs and outputs, which partially substitutes for the missing output schema, and it gives the key re-scan behavior. The only notable gap is the unexplained required app_id parameter, which prevents full completeness.

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

Parameters2/5

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

The schema has 0% description coverage and the description never mentions app_id at all. The only meaning comes from the parameter title 'App Id', which is minimal. The description should compensate for the missing schema detail, but it does not explain where the app_id comes from or how to obtain it.

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

Purpose5/5

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

The description names a specific verb ('List') and resource ('every input ... and output ...'), enumerating the exact fields returned for both. This clearly distinguishes list_controls from siblings like read_outputs and click, which target different aspects of the UI.

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

Usage Guidelines4/5

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

It provides explicit timing guidance: 'Call again after dynamic UI changes.' This tells the agent when to re-invoke the tool. However, it does not explicitly contrast it with sibling tools or state when not to use it, so it falls short of a full 5.

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