Architecture & Components

MCPA · 42 questions

• A server publishes a tool that takes no parameters, with its inputSchema set to null, and several clients refuse to use the tool. Which fix aligns with the 2026-07-28 tools specification?
• A weather tool declares an outputSchema that requires temperature, conditions and humidity fields. What does declaring this schema commit the server and its clients to?
• A tool named listusers on a revision 2026-07-28 server declares an outputSchema whose top-level type is an array of user objects. The developer also wants older clients that read only the content array to receive the data. Which approach follows the 2026-07-28 tools specification?
• A client receives two tools. The first tool's inputSchema has type, properties and required keywords but no $schema keyword. The second tool's schema declares $schema pointing at draft-07. How should the client interpret the two schemas?
• A client that implements only JSON Schema 2020-12 receives a tool whose inputSchema declares, through $schema, an older dialect that the client has never implemented. What does the specification require of the client?
• A tool's inputSchema contains a $ref that points at an https URL on a third-party host. The client's validator library is capable of fetching that URL automatically. What does the specification require by default?
• A security review finds that an untrusted server publishes an inputSchema with deeply nested anyOf and oneOf branches, and validating arguments against it ties up the client's validator for minutes. Which mitigation does the specification recommend?
• A shipping server wants to use form-mode elicitation to collect a customer's delivery details, including an array of address objects that each have street, city and postcode fields. What constraint does form mode impose on this design?
• A reporting tool's result must include a rendered chart, a short written summary, and a pointer to a full report that the client can fetch later without the report's contents being placed inline. Which combination of unstructured content types fits this result?
• A host displays garbled output whenever a charting tool returns an image content block. Inspection shows that the block's data field holds raw PNG bytes and its mimeType field is empty. Which fix aligns the result with the specification?
• A diagnostics tool returns a large log file. The server wants the host to show the log to the human user while signaling that it is not meant for the model's context. Which mechanism fits this intent?
• During a design review, a developer argues that a tool's structuredContent field makes the language model generate its reply in a schema-constrained format. How does the MCP specification describe structuredContent?
• A document server exposes a resource whose content is a PDF file rather than plain text. How should the server represent that content in its resources/read result?
• A vendor adds a meta key named dev.mcp/trace to carry its own tracing data in requests. A reviewer flags the key during code review. What is wrong with it?
• An architect is documenting the duties of the AI application that coordinates MCP connections on a user's behalf. Which set of responsibilities belongs to this host?
• In an MCP deployment, one component attaches the protocol version and its capabilities to every request it sends, and it communicates with exactly one server. Which participant is this?
• A component exposes tools, resources and prompts. Whenever it needs input from the user, it never sends its own JSON-RPC request; instead it embeds the need inside its reply to the client's request. Which participant is this?
• A code editor acting as an MCP host connects to a local filesystem server and to a remote error-tracking service. How many MCP client instances does the editor create for these connections?
• A server author asks a host vendor to forward the entire chat transcript with every tool call so that the server can produce better answers. Which MCP design principle governs the host's response?
• A team runs one MCP server locally over the stdio transport and another as a remote service over Streamable HTTP. How many clients does each kind of server typically serve?
• A startup hesitates to build an MCP server because it assumes the server must plan multi-step workflows, coordinate other servers and manage the model. What does the MCP design say about this division of work?
• A host aggregates tools from two connected servers, and each server exposes a tool named search. What disambiguation approach does the specification recommend?
• A client team proposes automatically approving every tool from any server whose serverInfo name contains the word Official. Why is this a poor design?
• An administrator configures a local MCP server that uses the stdio transport. Which party starts the server process?
• A company deploys an MCP server as an independent process that many clients reach over the network at a single endpoint URL. Which transport matches this deployment model?
• A platform team places a gateway between its hosts and several back-end MCP servers. Hosts connect to the gateway, and the gateway forwards calls to the back ends. How should the team reason about the gateway's protocol obligations?
• Under MCP revision 2026-07-28, where does each side communicate its capabilities?
• A client calls a tool on a server that cannot complete the call without asking the user a question, but the request's clientCapabilities in meta does not declare elicitation. What should the server return?
• A chat application connects to three MCP servers on the user's behalf. Which participant holds the full conversation history?
• A user asks an assistant to list today's open support tickets, which requires live data from an MCP server. Which sequence describes the flow?
• When an assistant uses an MCP tool, which pairing of roles is correct?
• A model keeps calling getinvoice when it should call getinvoicepdf, because both tools have one-line, nearly identical descriptions. What is the most effective first fix on the server side?
• Before the model runs, a host automatically attaches a project README, exposed by an MCP server, to the context it sends. Which primitive and control model does this illustrate?
• A user types a slash command that an MCP server offers as a prompt template with one argument. Which sequence follows?
• A host places each server's tool list in the model's context on every turn and wants better prompt-cache hit rates with its LLM provider. Which server behavior supports this goal?
• A host connects to dozens of MCP servers exposing hundreds of tools, and the tool definitions alone consume most of the model's context window. Which client pattern addresses this problem?
• A flight-booking tool receives a departure date that is already in the past. The model could fix the call if it were told what went wrong. How should the server report this problem?
• Midway through a tools/call, a server determines that the user must confirm a charge before it can continue. The client declared elicitation. Which sequence follows under revision 2026-07-28?
• During a conversation, a host receives notifications/tools/listchanged from a server on its subscriptions/listen stream. What should the host do before the model's next turn?
• A client lets the model write a short script that calls several MCP tools inside a sandbox, and only the script's final output returns to the model. What is this pattern called, and what does it improve?
• A team building a brand-new MCP server wants LLM completions to support the server's own internal reasoning. What does the 2026-07-28 specification recommend?
• In a single turn, the model asks for two tool calls on the same MCP server. How does the client send them and match each result to its call?