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

Beyond the annotations (readOnlyHint=false, destructiveHint=false), the description discloses important behavior: invoke runs a one-off tool execution without adding the MCP to the toolkit, returns connect or checkout links for auth/billing gaps with a retry instruction, and install/uninstall/subscribe/cancel are permanent/write actions requiring owner/admin. It also mentions installed_in_toolkit vs installed_in_workspace flags.

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 block of prose with multiple embedded clauses and a bilingual phrase ('pontualmente'), making it harder to scan. It contains valuable information, but structure is weak — no bullet lists or clear separation of the marketplace domain, prompt library, and billing/subscription behaviors. It is not concise given the number of concepts packed in.

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 complex multi-action tool with no output schema, the description covers the core flows, auth and payment edge cases, write permissions, installed flags, and the prompt library. Gaps remain: the 'resume' action is listed but never explained, and normal return value behavior for invoke/describe/search is not described. Still, the description is substantially complete for an agent to operate the tool successfully in most scenarios.

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 coverage, the description carries the full burden, and it does explain core parameters like action, tool_id, mcp_id (implicitly), query, and arguments. However, many parameters remain unexplained: limit, immediate, tier_slug, conversation, cancel_reason, cancel_comment, report_context, and most prompt_* parameters. The description compensates for part of the gap but leaves a large remainder undocumented.

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' — an in-platform catalog and runner for MCPs/tools, plus a prompt library. It states concrete verbs (search, describe, invoke, install, subscribe, request) and distinguishes this tool from siblings by focusing on discovery, one-off execution, and permanent installation.

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 flow guidance: search → describe → invoke, with a clear explanation of when to use invoke vs install ('prefer invoke for a single/occasional use', 'install only to make an MCP PERMANENT'). It also explains list_tools for currently callable tools, request_mcp for unmet needs, and that writes require workspace owner/admin.

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