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

Discloses many non-obvious behaviors beyond annotations: 'invoke works even when the MCP is NOT installed — it runs the tool pontualmente', 'returns a connect link' when credentials needed, 'returns a checkout/top-up link' when wallet empty, and 'Writes require workspace owner/admin.' Also notes search/describe flag installation status. 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 single dense paragraph, but it follows a logical flow from purpose to core steps, key caveats, and prompt library. Every sentence adds value, but it lacks structural formatting like bullet points or sections. It is not excessively verbose, but readability could be improved without losing information.

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 with 23 parameters, no output schema, and 14 actions, the description covers the main flows thoroughly, including auth, billing, ownership restrictions, and prompt library. It explains most parameter group semantics. However, a few parameters like immediate, tier_slug, and request_details remain unexplained, and the return structure is not detailed. Still, it is far more complete than typical descriptions for such a complex tool.

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 coverage is 0%, so the description carries the burden. It explains key parameters indirectly: action (all enum values), mcp_id, tool_id, arguments, prompt_* parameters for the prompt library. However, some parameters like limit, immediate, tier_slug, request_details, conversation are not explicitly described, though context may imply their use. Overall, it compensates well for the schema gap but not perfectly.

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 defines the tool as 'the official mcp.ai marketplace — the in-platform catalog of every MCP/tool, AND the way to run them.' It specifies a specific verb+resource (manage marketplace) and distinguishes it from siblings by describing its role in discovering, describing, and invoking MCPs, plus prompt library functions.

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?

Provides explicit usage flow: 'Core flow: action=search... → describe... → invoke RUNS that tool.' It also gives clear when-to-use guidance: 'prefer invoke for a single/occasional use' vs. 'Use install only to make an MCP PERMANENT.' Mentions alternatives like list_tools and search_prompts for different intents.

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