Boost (or demote) a specific symbol in PageRank-driven ranking by setting a multiplicative weight. Pinned symbols also boost their containing file via the same weight. Use to surface canonical examples or architectural keystones. Capped at 50 active pins per project. Returns JSON: { ok, pin? }.
AI agents use pin_symbol to create or update resources in Trace — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Trace environment.
The tool creates or modifies metadata about symbol rankings (pins) in a code analysis system. This is a reversible operation (pins can be removed, weights adjusted, or settings changed), with no destructive capability, no code execution, and no side effects beyond updating internal ranking weights. The blast radius is limited to ranking display and analysis output within the IDE/tool itself.
From the tool's definition Tool description states it 'boost (or demote) a specific symbol in PageRank-driven ranking by setting a multiplicative weight' and 'Pinned symbols also boost their containing file via the same weight'.
Documented attack patterns abuse exactly the kind of access pin_symbol gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Trace, and nothing reaches the server without passing your rules. This is the rule we recommend for pin_symbol:
{
"version": "1",
"default": "deny",
"tools": {
"pin_symbol": {
"limits": [
{
"counter": "pin_symbol_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}pin_symbol 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.
Free to start. No card required.
Boost (or demote) a specific symbol in PageRank-driven ranking by setting a multiplicative weight. Pinned symbols also boost their containing file via the same weight. Use to surface canonical examples or architectural keystones. Capped at 50 active pins per project. Returns JSON: { ok, pin? }. It is categorised as a Write tool in the Trace MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Trace MCP server in PolicyLayer and add a rule for pin_symbol: 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 Trace. Nothing to install.
pin_symbol 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 pin_symbol 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 pin_symbol. 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.
pin_symbol is provided by the Trace MCP server (nikolai-vysotskyi/trace-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 178 Trace tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
178 Trace tools catalogued and risk-classified — across an index of 42,500+ MCP servers.