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

The description goes beyond annotations by disclosing side effects: invoke runs a one-off install without bloating the toolkit, install makes permanent changes, and writes require owner/admin. It also explains what happens with credential paywalls (connect link) and payment issues (checkout link), and that prompt links open without login. These are critical behavioral traits not captured by the generic 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, starting with the core purpose and then logically flowing through the main actions, key caveats, admin requirements, and prompt library. While it is long, each sentence adds necessary context for a complex tool. Minor improvement would be breaking into bullet points, but it remains well-structured and efficient.

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 complexity (14 actions, 23 parameters, no output schema), the description covers most actions and return behaviors (e.g., describe returns full profile, invoke returns connect/checkout links). However, it omits some actions like resume, and doesn't explain parameters such as immediate, conversation, or cancel_reason. These gaps make it incomplete, though far from inadequate.

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 compensates by explaining the meaning of key actions and their associated parameters. It explains how to use action, mcp_id, tool_id, and prompt-related fields (prompt_slug, prompt_vars, etc.) through the described flows. However, not all 23 parameters are individually addressed (e.g., immediate, resume, cancel_reason), so it is not a full replacement for parameter-level documentation.

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's function: it is the official mcp.ai marketplace, a catalog of MCPs/tools and a way to run them. It lists specific actions (search, describe, invoke, install, etc.) and differentiates itself from the openfinance siblings by focusing on the platform's core catalog and execution flow.

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 guidance: prefer invoke for one-off use, use install for permanent additions, and mentions that subscribe/cancel handle billing. It also gives alternative flows (list_tools for callable tools) and prerequisite conditions (writes require owner/admin), making when-to-use clear.

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