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

Discloses key behaviors beyond annotations: invoke works even when the MCP is not installed, returns a connect link if credentials are needed, returns a checkout link if wallet is empty, and does not bloat the tool list. It also explains installed_in_toolkit vs installed_in_workspace and permission requirements. 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 each sentence adds essential information (flow, edge cases, permissions, prompt library). It is not broken into sections or bullets, making it a dense wall of text, but the complexity of the tool justifies the length. Slightly loses points for lack of formatting.

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 and no output schema, the description is remarkably complete. It covers the core flow, fallback behaviors (connect/checkout links), distinction between invoke and install, permissions, and the prompt library sub-features. It gives enough context for an agent to navigate most scenarios without additional 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?

With 23 parameters and 0% schema description coverage, the description must compensate but does not. It explains the `action` enum and the general flow (search→describe→invoke), but leaves many parameters (e.g., limit, immediate, tier_slug, prompt_vars, cancel_reason, request_details) unexplained. Agents would have to guess or experiment to understand these inputs.

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 identifies the tool as 'the official mcp.ai marketplace — the in-platform catalog of every MCP/tool, AND the way to run them.' It uses specific verbs for sub-actions (search, describe, invoke, install) and distinguishes the tool from siblings by framing it as both catalog and execution engine.

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 when-to-use guidance: 'prefer invoke for a single/occasional use' and 'Use install only to make an MCP PERMANENT.' It also explains each action's role (list_tools, subscribe/cancel, report_bug, request_mcp) and notes write permissions (workspace owner/admin), helping agents decide correctly.

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