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

The description adds significant behavioral context beyond the annotations: invoke runs tools one-off even when not installed, returns connect/checkout links for auth/payment, and install makes MCPs permanent. It also discloses permission requirements and how installed status is flagged, making behavior predictable. 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 dense but front-loaded with the core flow, and each sentence adds useful information without fluff. The structure of explaining the main flow, key invoke behavior, then other actions and prompt library is logical and appropriate given 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?

Given the tool's breadth (14 actions, 23 params, no output schema), the description covers most operational contexts: discovery, description, invoke, install, billing, bug reporting, and prompt library. It lacks explicit return-value details for some actions like search and list_tools, but overall it is largely complete.

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?

Schema description coverage is 0%, so the description must compensate, but it only elaborates on the main action-related parameters (action, tool_id, arguments) and prompt variables. Many other parameters like limit, query, conversation, cancel_reason, prompt_targets are left to inference from names, which is insufficient for a 23-parameter tool.

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 what the tool does: it is the official mcp.ai marketplace covering both discovery and execution of MCPs, plus a prompt library. It distinguishes itself by explaining the core search→describe→invoke flow and is further differentiated from siblings like authenticate and report_bug.

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 on when to use invoke versus install, when to use list_tools, subscribe/cancel, report_bug, request_mcp, and prompt library actions. It also notes the prerequisite that writes require workspace owner/admin, which helps the agent decide whether to proceed.

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