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

Annotations specify readOnlyHint=false, destructiveHint=false, openWorldHint=true, idempotentHint=false, and the description expands on this by disclosing that invoke runs tools one-off even when not installed, returns connect links for missing credentials, returns checkout links when the wallet is empty, 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 a dense, single-paragraph wall of text covering many features. It is information-dense but lacks structural breaks, making it harder to parse. While appropriate for the tool's complexity, it could benefit from clearer organization (e.g., bullet points or subsection headings).

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?

Despite the tool's complexity and lack of an output schema, the description covers the primary user journeys, describes key behavioral outcomes (e.g., invoke return behavior, install's permanence), and mentions the prompt library. It omits details on return formats and some edge cases, but overall provides enough context for an agent to operate.

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?

The schema has 23 parameters with 0% description coverage. The description explains the central actions (search, describe, invoke, install, etc.) and mentions relevant parameters like action, query, mcp_id, tool_id, and arguments. However, many parameters (e.g., cancel_reason, cancel_comment, report_context, request_details, immediate, tier_slug) are not covered, leaving gaps for those sub-actions.

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 that the tool is the official mcp.ai marketplace—the catalog and runner for MCPs/tools. It distinguishes itself from sibling tools by outlining the core search → describe → invoke flow and secondary prompt library functionality, making its multi-purpose nature explicit.

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 for actions: prefer invoke for single/occasional use, use install for permanent toolkit additions, use list_tools to see callable tools, and use subscribe/cancel for billing. It also explains when to use search_prompts/get_prompt/publish_prompt, and notes auth requirements for writes.

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