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

Annotations only indicate readOnlyHint=false, so the description carries much of the transparency burden. It discloses that invoke works without installing, returns connect links for credentials and checkout links for payments, requires owner/admin for writes, and notes the one-off install behind invoke. This is substantial, but a couple of specifics (e.g., what 'pontualmente' means exactly) could be expanded.

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 long single paragraph covering many facets, but it is well-organized by action and efficiently introduces the core flow and key distinctions. It is dense but not rambling. Slight splitting into sections could improve scannability, but it earns its length.

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 high parameter count (23), no output schema, and limited annotations, this description is remarkably complete. It covers the purpose, all major actions, permission requirements, credential/payment handling, and the prompt library. No significant gaps for an agent to choose and invoke the right action.

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 must explain the action enum and its role in dispatching. It does map many actions to their intended inputs (e.g., search_prompts, get_prompt, invoke), but many parameters like request_name, tier_slug, and prompt_targets are not explicitly tied to specific actions—though they are somewhat inferable.

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 marketplace as the official mcp.ai catalog and execution platform, with a core flow (search → describe → invoke) that distinguishes it from sibling tools. It explicitly covers capability requests like 'find an MCP that does X' and 'consulta um CPF', and differentiates invoke from install.

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 guidance on when to use each action: search to discover, describe to get details, invoke for one-off runs (works even when not installed), install for permanent addition, subscribe/cancel for billing, list_tools for callable now, and request_mcp for new builds. It also notes permission requirements for writes.

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