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

The description goes well beyond annotations by exposing key behaviors: invoke works even when the MCP is not installed, runs one-off without bloating the toolkit, returns connect/checkout links when credentials or payment are needed, and requires workspace owner/admin for writes. It also explains the distinction between installed_in_toolkit vs installed_in_workspace and the prompt library's login-free sharing, adding significant behavioral context.

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 that front-loads the tool's main purpose and flow. Every sentence adds substantive detail, including billing, auth, and prompt library features. However, its length and lack of structural formatting (bullets or section breaks) make it slightly harder to scan, though it remains appropriate 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?

The description covers the core actions, return behaviors (connect/checkout links, shareable prompt link), permission requirements, and the distinction between one-off invoke and permanent install. For a tool with 23 parameters and no output schema, it provides a strong overall picture. Minor gaps include exact return formats for list_tools and prompt operations, but these are inferable from context.

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 carries the burden of explaining parameters. It clarifies the meaning of the action enum values (search, describe, invoke, install, etc.) and key parameters like tool_id and mcp_id, but leaves several parameters undefined (e.g., immediate, tier_slug, limit, conversation, prompt_targets). While the names are somewhat self-explanatory, the lack of explicit definitions for all 23 parameters keeps this from being fully compensated.

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 — the in-platform catalog of every MCP/tool, AND the way to run them,' clearly stating its function. It distinguishes the tool from siblings by describing its core flow (search → describe → invoke) and its prompt library feature, making it unique among the listed sibling tools.

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 usage rules: 'prefer invoke for a single/occasional use', 'Use install only to make an MCP PERMANENT', and contrasts with 'list_tools lists what is callable right now'. It also references alternatives like 'request_mcp asks us to build a NEW MCP when nothing fits', offering clear when-to-use and when-not-to-use guidance.

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