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

Beyond the sparse annotations (readOnlyHint=false, openWorldHint=true), the description discloses key behavioral traits: invoke runs one-off without installing or bloating the tool list, returns connect links when credentials are needed and checkout links when payment is required (with 'retry' instruction), flags installed_in_toolkit vs workspace, and requires owner/admin for writes. No contradictions 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 information-dense and logically structured, moving from core flow to key distinctions to prompt library. It front-loads the primary purpose and uses a natural narrative. However, it is a dense wall of text that could benefit from bullet points or clearer section separation, and some redundancy exists (e.g., 'installed_in_toolkit vs installed_in_workspace' appears twice).

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 of this complexity (14 actions, 23 params, no output schema, minimal annotations), the description covers an impressive amount: the end-to-end workflow, auth/payment behavior, permission model, installed status flags, and the prompt library. Gaps remain: the 'resume' action is never mentioned, and parameters like immediate and tier_slug are absent. Yet overall it provides a strong operational context for an agent.

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 it only explains the 'action' parameter thoroughly and touches on mcp_id, tool_id, and prompt_slug implicitly. It does not explain key parameters like arguments, immediate, tier_slug, prompt_vars, cancel_reason, report_context, or request_details. This leaves agents guessing about the meaning and expected formats of most parameters.

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 states the tool is the 'official mcp.ai marketplace' — the central catalog and runtime for every MCP/tool. It clearly enumerates its purpose (search, describe, invoke, install, subscribe, prompt library) and differentiates it from the OpenFinance siblings, which are domain-specific. The verb 'catalog and run' plus the action list make the purpose unambiguous.

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 when-to-use guidance: the core flow (search → describe → invoke), when to prefer invoke over install ('Use install only to make an MCP PERMANENT... prefer invoke for a single/occasional use'), and permission requirements ('Writes require workspace owner/admin'). It also states what list_tools is for and how to handle credential/payment fallback. This is a model of usage direction.

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