Skip to main content
Glama

write_cache

Run a Houdini file cache node to render frames and verify the write actually succeeded on disk, reporting errors from the internal ROP with clear success or failure status.

Instructions

Execute a cache node, and report whether a cache actually appeared.

Foreground by default: Houdini shows its own progress dialog and the user can cancel. The call holds until the write finishes, however long that is; a client that hands a long call to a background task notifies you with the verdict when it lands. Do nothing else in Houdini meanwhile (every other call queues behind the write) and never poll the disk.

success and wrote_files reflect the files on disk and the errors of the node that did the writing -- a filecache delegates to an internal ROP and stays silent itself, so a failed write used to be reported as success. Errors are named with the node they came from.

Args: ctx: MCP context. node_path: Path to the cache node. frame_range: [start, end] frame range to render. Overrides the node's $FSTART/$FEND expressions for this and later writes. background: Save from a separate Houdini process (File Cache's own "Save to Disk in Background") so Houdini stays usable, at the cost of the user seeing no progress there. Saves the hip first, returns at once with status "launched"; follow it with get_cache_status. Use it only when asked to keep working while a cache writes. A verified foreground write turns the node's Load from Disk on.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
node_pathYes
backgroundNo
frame_rangeNo

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv0.1.0

TDQS

A4.9/5.0
Behavior5/5

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

With no annotations, the description carries the full burden and excels: it discloses foreground default, user-cancellation, blocking semantics, queueing, the 'do nothing else' constraint, failure semantics (success/wrote_files reflect disk and node errors, historical false-success), and the background process behavior including hip save and immediate 'launched' return. It also mentions verifying foreground write turns Load from Disk on. This is exemplary.

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 long but tightly packed with essential information. Every sentence adds value—behavioral rules, parameter semantics, and error reporting. It front-loads the core action and then layers necessary detail. A slight trim of the background paragraph could improve conciseness, but nothing is redundant or filler.

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

Completeness5/5

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

For a tool with 3 parameters and no output schema, the description covers everything an agent needs to call it correctly: what it returns (success/wrote_files semantics), how to handle background mode, what to avoid (polling, concurrent calls), and the side effects (Load from Disk). The mention of get_cache_status as a follow-up completes the loop. No critical information is missing.

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

Parameters5/5

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

Schema description coverage is 0%, but the description fully compensates: node_path is explained as the path to the cache node; frame_range is described as overriding $FSTART/$FEND for this and later writes; background is detailed with its separate-process behavior, hip save, immediate return, and situation to use it. Each parameter's meaning and side effects are covered beyond the schema's bare type.

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 opens with a specific verb and resource: 'Execute a cache node, and report whether a cache actually appeared.' This clearly distinguishes it from sibling queries like list_caches or get_cache_status, and names the relevant node type (cache node). The purpose is unambiguous and not a tautology.

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

Usage Guidelines5/5

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

The description gives explicit context for when to use foreground vs. background mode ('Use it only when asked to keep working while a cache writes'), warns never to poll the disk, and names the follow-up tool (get_cache_status). It also explains the blocking/queueing behavior so an agent knows not to issue concurrent calls. This is more than adequate.

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

Deploy Server

Other Tools