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

The description richly discloses side-effect behaviors beyond annotations: invoke works even when the MCP is not installed, returns connect/checkout links, and requires retry after user action. It also explicitly states that writes (install/uninstall/subscribe/cancel and one-off install behind invoke) require workspace owner/admin, adding meaningful context given readOnlyHint is false.

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?

Despite its length, the description is tightly packed with high-value information, progressing logically from core concept to workflow to edge cases to prompt library. Every sentence earns its place; it is neither bloated nor under-specified given the tool's complexity.

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 covers all major action families and the prompt library, making it quite complete for the tool's complexity. Minor gaps remain (e.g., the 'resume' action, parameter 'immediate' semantics), but these are niche relative to the primary use cases and the lack of an output schema is not an issue.

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 compensates well by explaining the semantics of key parameters (action, mcp_id, tool_id, arguments, prompt_slug, prompt_vars) within workflow examples. However, it omits some params like 'resume', 'immediate', 'tier_slug', and 'cancel_reason', though most self-named params remain inferable.

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 is exceptionally clear: it states the tool is 'the official mcp.ai marketplace' and outlines the core search → describe → invoke workflow. It clearly distinguishes this from sibling tools by positioning it as both the catalog and execution engine for MCPs.

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 gives explicit guidance on when to use each action: 'prefer invoke for a single/occasional use', 'Use install only to make an MCP PERMANENT', 'list_tools lists what is callable right now', and 'request_mcp asks us to build a NEW MCP when nothing fits'. This provides strong when/to-use and alternative recommendations.

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