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

The description goes far beyond the annotations: it reveals that invoke works even when the MCP is not installed, returns a connect link for missing credentials, returns a checkout/top-up link for paid tools with an empty wallet, and requires retry. It also warns that writes (install/uninstall/subscribe/cancel and the one-off install behind invoke) require owner/admin. No contradictions with annotations, readOnlyHint=false and destructiveHint=false are consistent.

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 long but appropriately dense for such a broad, multi-role marketplace tool. It front-loads the primary purpose and then structures into core flow, exceptions (invoke), permanent install, event-list, and the prompt-library subdomain. Minor noise like the 'consulta um CPF' example and the odd 'pontualmente' wording slightly they the focus, but most sentences earn their place.

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 its length, this description leaves important gaps: the action enum does not contain the highlighted "invoke" action, there is no explicit mention of the 'resume' action, and the schema does not define output behavior for most actions beyond the few links mentioned. With 23 parameters and no output schema, the description slightly explains the full operational contract.

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% description coverage in the schema, the description provides a strong conceptual map but not a full parameter mapping. It clarifies core infra-structural after action=search, describe, etc., and the prompt-library variables, but many parameters remain ambiguous: `tier_slug`, `immediate`, `conversation`, `cancel_reason`, and most `prompt_*` fields are only implied by context. This leaves the agent to guess how to populate several fields.

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 explicitly identifies the tool as the official mcp.ai marketplace — 'the in-platform catalog of every MCP/tool, AND the way to run them' — and enumerates its major actions (search, describe, install, subscribe/cancel) and the secondary prompt-library capability. It clearly separates this mega-tool from its siblings by positioning it as the central catalog and execution hub.

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 highly actionable usage rules: use install only to make an MCP permanent, prefer invoke for single/occasional use, use subscribe/cancel for billing, report_bug for feedback, and request_mcp for requesting new MCPs. It also explains shown require owner/admin for write operations, and flags installed_in_toolkit vs installed_in_workspace states.

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