AI agents use set_block_attrs to create or update resources in SiYuan MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your SiYuan MCP Server environment.
The tool creates or modifies block metadata/properties within SiYuan notes. This is a Write operation—it changes state but is reversible (attributes can be changed again). It does not delete data (Destructive), execute arbitrary code (Execute), or involve financial transactions (Financial).
From the tool's definition Tool name 'set_block_attrs' and description '设置块属性' (set block attributes) indicate modification of block properties. Sibling tools include 'delete_block' and 'append_block', confirming this server manages block operations.
Documented attack patterns abuse exactly the kind of access set_block_attrs gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and SiYuan MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for set_block_attrs:
{
"version": "1",
"default": "deny",
"tools": {
"set_block_attrs": {
"limits": [
{
"counter": "set_block_attrs_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}set_block_attrs 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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设置块属性. It is categorised as a Write tool in the SiYuan MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the SiYuan MCP Server MCP server in PolicyLayer and add a rule for set_block_attrs: 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 SiYuan MCP Server. Nothing to install.
set_block_attrs 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 set_block_attrs 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 set_block_attrs. 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.
set_block_attrs is provided by the SiYuan MCP Server MCP server (xgq18237/siyuan_mcp_server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 52 SiYuan MCP Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
52 SiYuan MCP Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.