Find the source location (file + line) where a symbol is defined.
AI agents call swift_get_symbol_definition to retrieve information from SwiftLens without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool performs read-only semantic analysis of Swift code by querying SourceKit-LSP to locate where symbols are defined. It returns file paths and line numbers, which is informational navigation with no side effects. The minimal blast radius and lack of any state-changing capability confirm low severity.
From the tool's definition Tool name is 'swift_get_symbol_definition' and description states it 'Find[s] the source location (file + line) where a symbol is defined' — a pure query operation that retrieves metadata about code structure without modifying, executing, or deleting anything.
Documented attack patterns abuse exactly the kind of access swift_get_symbol_definition gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and SwiftLens, and nothing reaches the server without passing your rules. This is the rule we recommend for swift_get_symbol_definition:
{
"version": "1",
"default": "deny",
"tools": {
"swift_get_symbol_definition": {}
}
}swift_get_symbol_definition is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Find the source location (file + line) where a symbol is defined. It is categorised as a Read tool in the SwiftLens MCP Server, which means it retrieves data without modifying state.
Register the SwiftLens MCP server in PolicyLayer and add a rule for swift_get_symbol_definition: 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 SwiftLens. Nothing to install.
swift_get_symbol_definition is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the swift_get_symbol_definition 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 swift_get_symbol_definition. 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.
swift_get_symbol_definition is provided by the SwiftLens MCP server (swiftlens/swiftlens). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 15 SwiftLens tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
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15 SwiftLens tools catalogued and risk-classified — across an index of 42,500+ MCP servers.