AI agents use linear_addAttachment to create or update resources in Linear — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Linear environment.
This tool creates or modifies data reversibly by attaching files to issues. It does not delete data (Destructive), execute code (Execute), move money (Financial), or trigger external operations beyond attachment storage. The blast radius is minimal—an incorrect attachment can be removed or replaced. Therefore, Write is the appropriate category at low severity.
From the tool's definition Tool name 'linear_addAttachment' and description 'Add an attachment to an issue' indicate a create/modify operation that adds data to an issue without deleting or executing code.
Documented attack patterns abuse exactly the kind of access linear_addAttachment gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Linear, and nothing reaches the server without passing your rules. This is the rule we recommend for linear_addAttachment:
{
"version": "1",
"default": "deny",
"tools": {
"linear_addAttachment": {
"limits": [
{
"counter": "linear_addattachment_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}linear_addAttachment stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
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Add an attachment to an issue. It is categorised as a Write tool in the Linear MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Linear MCP server in PolicyLayer and add a rule for linear_addAttachment: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Linear. Nothing to install.
linear_addAttachment is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the linear_addAttachment rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for linear_addAttachment. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
linear_addAttachment is provided by the Linear MCP server (tacticlaunch/mcp-linear). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 182 Linear tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
182 Linear tools catalogued and risk-classified — across an index of 42,500+ MCP servers.