Inspect a Substreams package (.spkg) to see its module graph (DAG), protobuf output types, and manifest metadata.
AI agents call inspect_package to retrieve information from Substreams Search MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves and queries information about package structure and configuration with no side effects. It does not create, modify, delete, or execute external operations. The blast radius of misuse is minimal—an attacker could learn about package internals but cannot alter them or trigger downstream actions.
From the tool's definition Tool inspects and reads metadata from a Substreams package file, returning its module graph (DAG), protobuf output types, and manifest metadata. The description uses 'inspect' and 'see', indicating retrieval without modification.
Attacks that exploit this kind of access
Inspect a Substreams package (.spkg) to see its module graph (DAG), protobuf output types, and manifest metadata. It is categorised as a Read tool in the Substreams Search MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Substreams Search MCP Server MCP server in PolicyLayer and add a rule for inspect_package: 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 Substreams Search MCP Server. Nothing to install.
inspect_package 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 inspect_package 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 inspect_package. 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.
inspect_package is provided by the Substreams Search MCP Server MCP server (paulieb14/substreams-search-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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