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

The description discloses important behaviors not captured by annotations: invoke runs a tool one-off without adding it to the toolkit, writes require workspace owner/admin, and invoke returns connect or checkout links for credential/payment requirements. It also explains the effects of install (permanent addition to toolkit), making side effects transparent. No contradiction with 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 front-loaded, opening with the tool's purpose and immediately presenting the core flow. Every sentence provides actionable information, though the single-paragraph format with many semicolons makes it harder to scan; a bulleted structure would improve readability. The length is justified by 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?

Given the tool's broad scope and the absence of an output schema, the description does an exceptional job of covering the main flows, return behaviors (profile, connect link, checkout link, shareable slug), permission requirements, and the distinction between one-off invoke and permanent install. It also covers the prompt library subsystem, making the description complete enough for a complex multi-action tool.

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?

The description adds meaning to the 'action' parameter by detailing what each action does and defines the roles of 'tool_id', 'arguments', and prompt-related parameters through the core flow and examples. However, with zero schema description coverage and 23 parameters, many parameters (e.g., limit, query, immediate, tier_slug, cancel_reason) lack explicit explanation, leaving the agent to infer their purpose from context.

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 explicitly identifies the tool as the 'official mcp.ai marketplace' and explains its dual role: cataloging every MCP/tool and running them. It outlines the core flow (search → describe → invoke) and enumerates the actions, clearly distinguishing this central marketplace tool from siblings like authenticate, connect, or report_bug.

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 guidance on when to use invoke vs install: 'prefer invoke for a single/occasional use' and 'Use install only to make an MCP PERMANENT'. It also explains when to use search, describe, list_tools, report_bug, request_mcp, and the prompt library actions, giving clear decision rules for alternative actions.

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