Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Beyond the sparse annotations, the description reveals that invoke can run tools without installing them, returns connect or checkout links for auth/payment, and that all writes require workspace owner/admin. It also mentions installed_in_toolkit vs installed_in_workspace flags, providing valuable behavioral context.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Although lengthy, the description is packed with distinct, necessary concepts: marketplace catalog, core flow, one-off invoke semantics, auth/payment links, install vs invoke, permission requirements, and the prompt library. The information density is high with no filler or repetition.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The description thoroughly covers the main MCP marketplace workflow and most key actions, but it omits the 'resume' action and gives no explanation for prompt-library parameters or administrative fields like immediate and tier_slug. Given the tool's complexity and the absence of an output schema, these gaps mean it is not fully complete.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

With 0% schema description coverage, the description takes on the burden of explaining parameters. It gives meaning to the action enum and implies roles for mcp_id, tool_id, and arguments through the core flow. However, many parameters (prompt_slug, prompt_vars, conversation, immediate, tier_slug, etc.) remain undefined, leaving the full 23-parameter surface only partially explained.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with 'The official mcp.ai marketplace — the in-platform catalog of every MCP/tool, AND the way to run them,' clearly identifying the tool as both a catalog and an execution runtime. It then enumerates the core flow (search → describe → invoke) and lists all sub-actions, distinguishing it from sibling tools like authenticate and toolkit_info.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly instructs when to use invoke vs install: 'prefer invoke for a single/occasional use' and 'Use install only to make an MCP PERMANENT.' It also clarifies the roles of list_tools, request_mcp, and report_bug, providing direct guidance for choosing among alternatives.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.