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

The description goes beyond the annotations by disclosing that invoke works even when the MCP is not installed, runs one-off without bloating the toolkit, and may return connect or checkout links requiring user action. It also states that writes (install/uninstall/subscribe/cancel and the one-off install behind invoke) require workspace owner/admin, adding important context not present in the annotations.

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?

The description is informative but overly long, packing many details into a single paragraph. It front-loads the core purpose well, but the extensive enumeration of actions and edge cases could be more concise and better structured with separation or bullet points. Every sentence adds value, but the wall-of-text format hurts readability.

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?

Despite the high complexity (23 params, no output schema, many actions), the description covers a wide range of behavioral contexts: core flow, permissions, missing credential/payment scenarios, installed flags, and the prompt library. It is missing some parameter-level details and structured return format information, but the overall narrative provides substantial context for an agent to understand the tool's capabilities.

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 23 parameters and 0% schema description coverage, the description needed to compensate by explaining parameters, but it only narratively references action values like 'search' and 'invoke' without systematically defining parameters like limit, query, mcp_id, tool_id, arguments, immediate, tier_slug, prompt_vars, etc. This leaves significant ambiguity for an agent trying to construct valid calls.

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 clearly states the tool is the official mcp.ai marketplace that serves as both the catalog of MCPs/tools and the way to run them. It explicitly covers capability requests and distinguishes the marketplace from other tools by detailing its core flow (search, describe, invoke) and listing specific actions like install, subscribe, and prompt library functions.

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 provides explicit when-to-use and when-not-to-use guidance, such as 'use install only to make an MCP PERMANENT' and 'prefer invoke for a single/occasional use.' It also explains when to use search/describe, list_tools, subscribe/cancel, report_bug, request_mcp, and the prompt library actions, giving clear alternatives within the same tool.

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