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update_vng

Update an AWS VNG launch spec configuration via JSON updates. Requires confirmation to execute.

Instructions

DESTRUCTIVE: Update an AWS VNG (launch spec) configuration. Requires confirm=true. Pass updates as a JSON string.

The Spot.io API requires userData to be base64-encoded. This tool auto-encodes plaintext userData by default (set encode_user_data=false to opt out if you're passing already-encoded data).

Args: vng_id: The VNG/launch spec ID (e.g. ols-abc12345) updates_json: JSON string of fields to update (e.g. '{"resourceLimits": {"maxInstanceCount": 20}}') confirm: Must be true to execute. Safety guard. account_id: Optional account ID. Defaults to SPOTINST_ACCOUNT_ID env var. auto_apply_tags: If true, update resource tags without triggering a roll. If None (default), omitted from request (Spot default applies). encode_user_data: If true (default) and userData is present but not already base64, base64-encode it before sending. Set false to pass through as-is.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
vng_idYes
updates_jsonYes
confirmNo
account_idNo
auto_apply_tagsNo
encode_user_dataNo

Output Schema

TableJSON Schema
NameRequiredDescriptionDefault
resultYes
Behavior3/5

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

Discloses destructive nature, confirm requirement, and auto-encoding of userData. With no annotations, the description carries full burden; it lacks details on synchronous/asynchronous behavior, return format, or error conditions.

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?

Succinctly front-loaded with 'DESTRUCTIVE' and purpose, followed by a structured parameter list. Every sentence provides value, no redundancy.

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?

Covers essential aspects including destructive nature, confirm guard, encoding, and optional parameters. Minor gaps: no mention of output despite presence of output schema, and no error handling or prerequisites.

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 coverage is 0%, but the description exhaustively explains all 6 parameters with example values and behaviors, fully compensating for missing schema descriptions.

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?

Clearly states 'Update an AWS VNG (launch spec) configuration' with a prominent 'DESTRUCTIVE' label. Distinguishes from siblings like create_vng, delete_vng, and get_vng.

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?

Provides instructions on required confirm=true, JSON string updates, and encoding behavior. Does not explicitly contrast with alternatives but context from sibling names clarifies when to use this tool.

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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