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

The description discloses key behavioral traits well beyond the sparse annotations: invoke runs a tool one-off without adding to the toolkit, writes require workspace owner/admin, credential/payment issues return connect/checkout links, and search/describe flag installed status. It also mentions the prompt library's behavior with shareable links. All of this adds meaningful context that the annotations alone do not provide.

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 a single dense paragraph but is front-loaded with the tool's identity and each clause adds operational detail. It covers a lot of ground without redundant wording, though it would be easier to parse if broken into sections (MCP flow vs prompt library). Given the tool's complexity, the length is justified, and there is no obvious padding.

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 14 actions, 23 parameters, and no output schema, the description covers the main workflows, permission requirements, and the install-versus-invoke distinction. It does not explicitly mention the `resume` action, and some parameters receive no explanation, but the core functionality and edge cases (credentials, payment, owner/admin) are addressed, making it largely complete for practical use.

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 coverage, the description must compensate and largely does: it explains the core `action` enum values (search, describe, invoke, install, subscribe, cancel, report_bug, request_mcp, list_tools, and the prompt actions) and gives context for `tool_id`, `prompt_slug`, and the overall routing logic. However, several parameters such as `tier_slug`, `immediate`, `conversation`, and `prompt_targets` are not explicitly mentioned, so coverage is strong but not complete.

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 clear identity: 'the official mcp.ai marketplace — the in-platform catalog of every MCP/tool, AND the way to run them.' It goes on to describe a concrete core flow (search → describe → invoke) and distinguishes it from sibling financial tools by framing it as a catalog/runner rather than a domain-specific service. This goes beyond a vague 'marketplace' label.

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?

Explicit guidance is provided: 'Use install only to make an MCP PERMANENT in the active toolkit... prefer invoke for a single/occasional use.' It also explains when to use search/describe/invoke, clarifies that invoke works without installation, and outlines the roles of list_tools, subscribe/cancel, and prompt-specific actions, giving strong when-to-use versus alternative guidance.

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