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

The description adds substantial behavioral context beyond annotations: invoke runs uninstalled tools without bloating the toolkit, returns connect/checkout links on auth/payment failures, and writes require owner/admin. It also notes the flagging of installed_in_toolkit vs installed_in_workspace, giving the agent a clear model of side effects. 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 long but every sentence adds value, covering the main flow, edge cases, and the secondary prompt library feature. It is well-organized in a logical progression, though it could benefit from more structural formatting (e.g., bullets) but remains efficient for 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?

For a tool with 23 parameters, no output schema, and many actions, the description is remarkably complete. It covers discovery, detailed profiles, invocation, permanence, auth, billing, permissions, and the prompt library. It provides the agent with enough context to select and invoke the correct action and parameters without needing additional external documentation.

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?

Even though schema description coverage is 0%, the description explains the key parameters implicitly: action (with its enumeration via flow steps), mcp_id/tool_id for describe/invoke, arguments for invoke, and prompt-related fields for the prompt library actions. However, parameters like limit, immediate, tier_slug, and cancel_reason are not explicitly described, but their names and defaults make them somewhat 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 clearly states the tool is the official mcp.ai marketplace, combining a catalog of MCPs/tools with the ability to run them. It names specific actions like search, describe, invoke, and install, and distinguishes it from siblings by covering both MCP discovery and running, as well as the prompt library.

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 an explicit core flow (search → describe → invoke) and explicit guidance on when to use invoke vs install, including the note that invoke is for one-off use while install is for permanent toolkit additions. It also advises on auth/billing link retries and mentions owner/admin permission requirements for writes.

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