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

Beyond the annotations, it discloses key behaviors: invoke runs a tool one-off even when not installed without bloating the tool list, credentials trigger a connect link, empty wallet triggers a checkout/top-up link, writes require workspace owner/admin, and installed state is flagged in search/describe. These are substantive operational details that annotations alone would not convey.

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 dense but front-loaded with the marketplace identity and core flow. It uses run-on sentences and a single unbroken paragraph rather than structured bullets, but nearly every clause earns its place given the tool's 14 actions and 23 parameters.

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 primary workflows, auth/payment edge cases, permission requirements, installed-vs-invoked semantics, and the prompt library. Minor gaps remain: resume and immediate are not explained, and the exact return shapes of several actions are not specified, but overall it is substantially complete.

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 0% schema description coverage, the description must compensate heavily, and it does explain the central action parameter (search/describe/invoke/install/list_tools/etc.). However, several params remain undocumented or ambiguous, including immediate, tier_slug, resume, conversation, prompt_targets, and cancel_reason. Many names are self-explanatory, but the compensation is only partial.

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 is unambiguous: it identifies the tool as the official mcp.ai marketplace, the in-platform catalog of MCPs/tools, and the mechanism to run them. It clearly differentiates itself from siblings by covering the full search/describe/invoke workflow and the prompt library, not just a single function.

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: 'Core flow: action=search discovers MCPs by intent → describe returns one MCP's full profile ... → invoke RUNS that tool.' It also directly contrasts invoke vs install ('prefer invoke for a single/occasional use' vs 'Use install only to make an MCP PERMANENT') and points to request_mcp 'when nothing fits.'

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