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

The description goes well beyond the sparse annotations, disclosing key behaviors: invoke runs uninstalled MCPs on a one-off basis, credential gaps return a connect link, empty wallets return a checkout/top-up link, and the agent should retry after the user resolves the link. It also states that writes require workspace owner/admin privileges, adding operational context absent from 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 dense and long, but the length is largely justified given the tool's 14 actions and multiple sub-flows. It is front-loaded with the core purpose and uses clear signposts like 'Core flow', 'KEY', and 'Use install only' to structure the information. A few promotional or repetitive phrases exist, but every major sentence contributes operational guidance.

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?

Given the tool's high complexity, no output schema, and very minimal annotations, the description is remarkably complete. It covers the end-to-end discovery→describe→invoke flow, explains one-off vs permanent installation, describes auth and payment interruption behaviors, touches on billing actions, bug reporting, MCP requests, and the separate prompt-library feature, and even notes ownership requirements.

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 and 23 parameters, the description must carry the parameter-meaning burden. It explains the action enum and key concepts like tool_id, prompt_vars, and publish_prompt's shareable slug, but it does not map several parameters (e.g., limit, query, message, arguments, immediate, tier_slug, conversation, prompt_targets) or give their exact usage. It compensates for the main flow but leaves clear semantic gaps.

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 a specific verb and resource: 'the official mcp.ai marketplace — the in-platform catalog of every MCP/tool, AND the way to run them.' It clearly distinguishes the marketplace from sibling tools by framing it as the discovery, description, invocation, and management layer, while siblings like authenticate and report_bug have narrow scopes.

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 which action: 'prefer invoke for a single/occasional use', 'Use install only to make an MCP PERMANENT in the active toolkit', and 'list_tools lists what is callable right now.' It also tells the agent what to do in credential/payment edge cases and names alternatives like request_mcp and report_bug.

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