Compose Preview Catalogs

ui_builder_get_design

Read one design: its whole document — nodes, slots, properties, modifiers, state variables and catalog pin — plus the revision to quote as baseRevision when editing it. The catalog the design pins is left out unless includeCatalog is true: it is the same for every design on the pin, ui_builder_list_catalogs serves it, and it is most of the bytes. home, at the top of the reply, is where the design is canonical ({kind: server, url, designId} or {kind: repo, path}): edit it there. It is absent when none is recorded (a design made before homes existed, or on a host with no public origin), and then the canonical home cannot be verified. On hosts with design discussions, unacknowledgedComments is the number of comment threads this actor has not acknowledged; a nonzero count also carries the bounded comments notice.

Input Schema

TableJSON Schema

Name	Required	Description
`token`	No	A grant token from poll_access, when you cannot set the X-Compose-Preview-Token header yourself — an MCP client fixes its headers at connect time, so this is how a token approved during this session is used in it. Prefer the header where you control it.
`designId`	Yes
`revision`	No	A past revision. Omit for the current one.
`agentName`	No	Optional agent/client name shown to design viewers; self-reported.
`agentModel`	No	Optional current model name shown to design viewers; self-reported. Omit when unknown.
`includeCatalog`	No	Embed the pinned catalog's whole CatalogCapabilityV1 in the snapshot, as the released shape does. Defaults to false.

Output Schema

TableJSON Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

Changed2 schema fields changedOct 4, 2026

addedInput schema / properties / agentModel

Added value: +{
+  "description": "Optional current model name shown to design viewers; self-reported. Omit when unknown.",
+  "maxLength": 80,
+  "type": "string"
+}

addedInput schema / properties / agentName

Added value: +{
+  "description": "Optional agent/client name shown to design viewers; self-reported.",
+  "maxLength": 80,
+  "type": "string"
+}

Changed1 schema field changedSep 30, 2026
- changedOutput schema / (root)
```
Previous value: -nullNew value: +{
+  "type": "object"
+}
```
First observedSep 30, 2026

TDQS

A4.3/5.0

Behavior4/5

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

With no annotations, the description carries the full burden and does well: it explains why the catalog is omitted by default (same for every design on the pin, most of the bytes), the `includeCatalog` default, and the exact conditions under which `home` is absent and unverifiable. It stops short of stating auth/permission requirements, though the token semantics live in the schema.

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?

Front-loaded with the core action and its contents, then the catalog caveat, then the optional output-field notes. Dense and largely waste-free, though the trailing `home` and `unacknowledgedComments` sentences lengthen it beyond what a caller strictly needs to invoke it.

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?

For a read tool with an output schema, the description is complete on invocation and semantics: it flags the two non-obvious fields (`home`, `unacknowledgedComments`), the catalog default, and the revision-to-quote. No annotation coverage means it must carry behavior alone, which it largely does.

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

Parameters4/5

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

Schema coverage is 83% (>80%), so baseline is 3; the description lifts it by adding rationale for `includeCatalog` beyond the schema's terse text and by tying `revision`/`baseRevision` to the edit workflow. It adds value without restating the schema.

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?

States a precise verb and scope — 'Read one design: its whole document — nodes, slots, properties, modifiers, state variables and catalog pin' — and immediately names the editing-relevant payload (`baseRevision`). An agent can distinguish this single-design full-document read from list/diff/check siblings without opening a schema.

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?

Routes the agent on the catalog decision ('it is ... served by ui_builder_list_catalogs') and tells it what to do with `home` ('edit it there'). It does not explicitly contrast this tool against the other read siblings (list_designs, view, check_design), so the guidance is clear but not exhaustive.

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

All Compose Preview Catalogs tools Inspect

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.