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Control Plane

by io.cpln

Mount Volumeset to Workload

mount_volumeset_to_workload
Idempotent

Attach a volumeset to a workload — mounts into the FIRST container only. Creates the volumeset when missing; size/fileSystemType/performanceClass apply ONLY on that create path and are ignored when the volumeset already exists. Workload-type rule: ext4/xfs (read-write-once) volumesets require a stateful or vm workload and bind to ONE workload; shared-filesystem volumesets mount on any workload type. Workload types are immutable — switching requires deleting and recreating the workload (plan downtime). Recommended reading before first use: get_cpln_skill("stateful-storage") — the runbook for this tool family (read once per session).

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
gvcYesGVC slug (lowercase kebab-case). Use the GVC the user named; otherwise discover with list_resources (kind="gvc") and let them choose — never guess (a wrong GVC targets the wrong environment).
orgYesOrganization slug (lowercase kebab-case). NEVER guess — if the user has not named one, ask. On org-not-found, stop and ask; do not retry variants.
sizeNoInitial capacity in GB — CREATE-ONLY (ignored when the volumeset already exists; expand_volumeset grows it). Required when creating. Min 10 (200 for high-throughput-ssd), max 65536.
tagsNoOptional tags for the volumeset; use them like Kubernetes labels for governance and search.
mountPathNoMount path inside the container (defaults to /mnt/{volumesetName}). Normalized before validation (".." resolved, "//" collapsed); reserved paths /dev, /dev/log, /tmp, /var, /var/log are rejected.
descriptionNoVolumeset description so operators know what data lives here (treat it like a Kubernetes annotation).
workloadNameYesExisting workload name to mount storage into; pass the name only, not a link.
volumesetNameNoOptional volumeset resource name, not a link. Omit to use {workloadName}-vol. If this volumeset does not exist yet, `size` is required so the tool can create it before mounting.
fileSystemTypeNoFile system type — CREATE-ONLY (ignored when the volumeset already exists); default xfs. ext4/xfs are read-write-once (stateful or vm workloads only); shared is read-write-many (any workload type).
recoveryPolicyNoWhat a NEW replica does when a matching volume already exists: "retain" (default) reuses the data, "recycle" starts fresh (schema/volumeSpec recoveryPolicy).
performanceClassNoPerformance class — CREATE-ONLY (ignored when the volumeset already exists); default general-purpose-ssd. high-throughput-ssd requires size ≥ 200; shared pairs only with fileSystemType shared.

Output Schema

TableJSON Schema
NameRequiredDescriptionDefault
okYesWhether the call succeeded.
dataNoThe full machine-readable result — list rows, the resource object, query results. Read THIS, not just the summary.
summaryYesOne-line summary of the result.
nextStepsNoRecommended follow-up actions for this task, in order.

TDQS

A4.9/5.0
Behavior5/5

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

Beyond the annotations (idempotentHint=true), the description reveals critical behaviors: mounting only into the FIRST container, the create-only nature of size/fileSystemType/performanceClass, workload-type constraints, and the immutable workload-type consequence that requires delete/recreate downtime. This is substantial added transparency.

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?

The description is compact given the tool's complexity, with approximately five sentences each carrying essential information. It front-loads the primary action, then covers create-only semantics, workload-type rules, immutability warning, and a reference to the skill runbook—no filler or redundancy.

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 11 parameters, conditional create semantics, and workload-type restrictions, the description covers all key behavioral caveats and even references a runbook for deeper context. Since an output schema exists, return values need not be explained. The description is sufficiently complete for correct tool selection and invocation.

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?

The input schema already provides 100% parameter descriptions, including the create-only semantics for size/fileSystemType/performanceClass and workload-type rules for fileSystemType. The tool description reinforces these in a concise summary, adding a holistic view that ties parameters to the overall flow, but does not introduce entirely new parameter information.

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+resource: 'Attach a volumeset to a workload — mounts into the FIRST container only.' This unambiguously identifies the tool's action and scope, and distinguishes it from siblings like create_volumeset, expand_volumeset, and create_workload.

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 clearly states when to use this tool (attach volumeset, optionally creating it) and when not (e.g., size is ignored if the volumeset already exists, implying expand_volumeset for growth). It also explains workload-type requirements and points to get_cpln_skill('stateful-storage') for first-use guidance, giving explicit context and alternatives.

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

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TDQS

A4.1/5.0
Disambiguation5/5

Every tool targets a distinct resource/action pair (e.g., get_resource vs get_resource_schema, list_deployments vs list_workload_replicas) and descriptions clearly differentiate purposes. No two tools appear to do the same thing.

Naming Consistency5/5

All tools follow a verb_noun snake_case pattern (create_gvc, update_workload, list_resources, query_metrics) with consistent verbs. The few imperative verbs (browse, build, mount) still maintain the same verb-first structure.

Tool Count1/5

With 55 tools, this server far exceeds the typical well-scoped 3-15 tool range. While each tool appears purposeful, the sheer number creates selection overhead and falls into the extreme 50+ category on the rubric.

Completeness4/5

The surface covers nearly the full Control Plane lifecycle: CRUD for GVC, workload, identity, policy, volumeset, and domain, plus observability, templates, image builds, and Terraform. Minor gaps include referenced but missing configure_workload_* tools and no secret creation/deletion (by design).

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