bl-halo-mcp

Overview Schema Source Related Servers Discussions Admin

halo_device

Control Brilliant Labs Halo and Frame smart glasses: manage BLE connections, display text and images, capture photos, access IMU and audio, and run Lua scripts or Noa queries.

Instructions

Halo / Frame glasses controller (portmanteau).

Return Format

{success, message, result?, error?, suggestions?, has_more?}.

Examples

await halo_device("status") await halo_device("show_text", text="Hello Halo") await halo_device("capture_photo")

Input Schema

TableJSON Schema

Name	Required	Description
`text`	No	Text / Lua source / question. Required for: show_text, run_lua, deploy_lua, noa_ask, miniapp_create.
`limit`	No	Page size (1-100). Used by: list_photos, list_lua_apps, tap_history.
`offset`	No	Page offset. Used by: list_photos, list_lua_apps.
`lua_name`	No	Lua filename. Required for: deploy_lua.
`image_b64`	No	Base64 image. Required for: show_image.
`operation`	Yes	One of: status, list_devices, connect, disconnect, show_text, show_image, clear_display, capture_photo, list_photos, imu_read, tap_history, play_audio, record_audio, run_lua, list_lua_apps, deploy_lua, get_lua, delete_lua, noa_ask, miniapp_create, firmware_info.
`duration_s`	No	Audio seconds (1-30). Used by: play_audio, record_audio.

Output Schema

TableJSON Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.3.0Sep 26, 2026

TDQS

C2.6/5.0

Behavior2/5

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states the return format and gives examples, but does not disclose side effects, state changes, error handling, or system impact. Operations like 'connect', 'disconnect', 'clear_display', and 'deploy_lua' imply significant behavioral consequences that are left completely unaddressed.

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?

The description is remarkably concise, with a one-line intro, a return-format section, and three examples. This structure is efficient and front-loaded, wasting no words. It could be longer to cover more operations, but as a concise spec it is well-organized.

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

Completeness2/5

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

This is a complex tool with 7 parameters and 20 operations, yet the description offers only a return format and three examples. It does not explain how operations relate to parameters, list prerequisites, or note any special cases. An agent would be ill-equipped to use it correctly for operations beyond the examples, making it incomplete for the tool's complexity.

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?

The schema covers all parameters with detailed descriptions (coverage 100%), so the description does not need to add parameter semantics. The examples illustrate usage but do not add meaning beyond the schema. The description's contribution is minimal, matching the baseline of 3 for high schema coverage.

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

Purpose3/5

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

The description labels it a 'Halo / Frame glasses controller' but does not clearly state what the controller does beyond that. Examples show specific operations like 'status' and 'capture_photo', giving a hint of its scope, but the purpose remains vague and fails to differentiate it from siblings like halo_help or halo_dashboard. A more explicit statement like 'Perform operations on Halo/Frame glasses' would improve clarity.

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

Usage Guidelines2/5

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

The description provides no guidance on when to use this tool versus its sibling tools (halo_help, halo_shutdown, halo_dashboard). It neither lists conditions for its use nor mentions alternatives or exclusions. An agent would have to infer usage from the operation list, which is not stated in the description.

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

Deploy Server