Sites with a broken MCP server card

What this report returns

An MCP server card advertises a site's Model Context Protocol server so agents can discover and connect to it.

A row appears here when any of these is wrong, worst first:

• Invalid JSONThe published card doesn't parse as JSON, so agents can't read it at all.Fix Serve valid JSON (check for trailing commas or comments; validate with a JSON linter).
• Missing URLThe card declares an endpoint that is not an absolute http(s) URL (such as "example.com/mcp", missing its scheme), so a client cannot connect to it. A card with no endpoint at all is not flagged: the server-card format makes it optional.Fix Give the full URL, e.g. "remotes": [{ "type": "streamable-http", "url": "https://mcp.example.com/mcp" }].
• Endpoint Not MCPThe endpoint the card advertises answered an MCP handshake with a normal HTTP 2xx page instead of a JSON-RPC reply, so no MCP client can connect to it: the card points somewhere real, but not at an MCP server.Fix Point the card at a working MCP Streamable HTTP endpoint, e.g. "url": "https://mcp.example.com/mcp", or withdraw the card until one exists. Only a 2xx non-JSON-RPC answer sets this: a 401 or 403 (authorization may be required) and an unreachable endpoint never do.
• Endpoint UnavailableEvery endpoint the card advertises answered HTTP 404 or 410, so the card points only at addresses that do not exist and an agent has nowhere to connect.Fix Publish a working MCP endpoint at the advertised URL, or remove the declarations that are no longer served. A 401 or 403 is not this (authorization may be required), and neither is a timeout.
• Tool Missing NameA tool in the server's tools/list has no name, and the name is the identifier a client calls, so that tool can never be invoked.Fix Give every listed tool a unique name.
• Tool Missing Input SchemaA listed tool declares no inputSchema, so an agent has no way to build a valid call to it.Fix Give every tool a JSON Schema for its parameters, e.g. {"type":"object","properties":{}} for a tool that takes none.
• Duplicate Tool NameTwo listed tools share a name. MCP defines the name as the tool's unique identifier, so a call naming it is ambiguous and a client may invoke the wrong one.Fix Give every tool a distinct name.
• Credential ExposedThe public server card includes a literal credential or a secret input default that readers can use.Fix Remove the value, rotate the credential and prompt authorized users through a secure channel.
• Sensitive Header ParameterA tool parameter named like a credential (password, token, API key) is marked x-mcp-header, so clients on MCP 2026-07-28 or later copy it into an HTTP header every proxy and log can read; MCP says servers should not do this.Fix Remove x-mcp-header from it and take credentials through authorization instead.
• Tool Missing DescriptionA listed tool has no description, so an agent can see the tool exists but cannot tell what it does or when to call it, and will skip it.Fix Describe what each tool does and when to use it, e.g. "description": "Look up current order status by order id".
• Insecure EndpointThe card advertises a public MCP endpoint on plain http://, so every tool call and its arguments, and the access token when the server asks for one, travel unencrypted. A Lumar bar: the transport spec states no scheme rule.Fix Serve the endpoint over https and advertise "url": "https://example.com/mcp".
• Unknown Method AcceptedThe endpoint answered a JSON-RPC method it does not implement with a result rather than an error, so a client cannot tell a supported call from an unsupported one.Fix Return a JSON-RPC error with code -32601 for methods the server does not implement.

(A missing transport is shown for context but is informational.)

Security checks are provisional; precision has not yet been measured. A clean row is not a security assessment.

The columns it shows

Every defect this technology can carry is a column in the grid, worst first, so nothing is hidden behind a filter you have to know to apply.

• Hosthost
• MCP Server ValidmcpServerValid
• MCP Server Conformance Issue DetectedmcpServerConformanceIssueDetected
• MCP Server Security Risk DetectedmcpServerSecurityRiskDetected
• MCP Server FindingsmcpServerFindings
• MCP Server Endpoint URLmcpServerEndpointUrl
• MCP Server TransportsmcpServerTransports
• MCP Server Tool NamesmcpServerToolNames
• MCP Server Invalid JSONmcpServerInvalidJson
• MCP Server Missing URLmcpServerMissingUrl
• MCP Server Endpoint Not MCPmcpServerEndpointNotMcp
• MCP Server Endpoint UnavailablemcpServerEndpointUnavailable
• MCP Server Tool Missing NamemcpServerToolMissingName
• MCP Server Tool Missing Input SchemamcpServerToolMissingInputSchema
• MCP Server Duplicate Tool NamemcpServerDuplicateToolName
• MCP Server Credential ExposedmcpServerCredentialExposed
• MCP Server Sensitive Header ParametermcpServerSensitiveHeaderParam
• mcpServer HTTPS DowngrademcpServerInsecureRedirect
• MCP Server Internal EndpointmcpServerInternalEndpoint
• MCP Server Tool Missing DescriptionmcpServerToolMissingDescription
• MCP Server Insecure EndpointmcpServerInsecureEndpoint
• MCP Server Unknown Method AcceptedmcpServerUnknownMethodAccepted
• MCP Server Missing TransportmcpServerMissingTransport
• MCP Server Stale EndpointmcpServerStaleEndpoint
• MCP Server Partially AssessedmcpServerPartiallyAssessed
• Ruleset VersionrulesetVersion
• Security Check StatussecurityCheckStatus
• Related Security FrameworkssecurityFrameworkReferences

About MCP server card

Advertises a Model Context Protocol endpoint agents can call.

Read how MCP server card is checked, including the specification it is validated against and a worked correct and broken example.

Running it

This report comes with Agentic Readiness in Lumar and appears on every crawl of any project that has it turned on. See the whole set, or check a single URL with the scanner on this site, which runs the same code with no account.

Get Lumar pricing →