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

Even with annotations, the description adds important behavior beyond readOnlyHint/openWorldHint: non-installed invocation runs one-off without bloating the tool list; credential needs return a connect link; empty wallet returns a checkout link; install is permanent; and write actions require owner/admin. No contradiction 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 long but each section earns its place—the core flow is front-loaded, and the detail on one-off invoke vs install provides practical guidance. Faceted formatting would improve skimmability, but for a 23-param multi-action tool the length is reasonably justified.

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?

The description tells what actions return: 'describe returns one MCP's full profile', 'invoke returns a connect or checkout link when needed', and 'publish_prompt saves a prompt and returns a shareable mcp.ai/p/<slug> link.' It does not detail sentinel behavior for every sub-action, but the main flows are sufficiently covered for a tool with no output schema.

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 schema_description_coverage = 0% and 23 optional params, the description compensates for the core parameters (action, query, mcp_id, tool_id, prompt_body/prompt_vars) by describing their role in the workflow. However, several parameters such as limit, immediate, conversation, cancel_comment, report_context, request_details, and prompt_targets are never semantically explained; the mass-style description is obliged to fill this gap better.

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 states a clear purpose: it is the 'official mcp.ai marketplace — the in-platform catalog of every MCP/tool, AND the way to run them.' It enumerates the core flow (search → describe → invoke) and the prompt-library features with specific verbs, distinguishing this umbrella tool from sibling tools like report_bug, toolkit_info, and sefaz_mg_certidao_debitos_consultar.

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 advice: 'Use install only to make an MCP PERMANENT', 'prefer invoke for a single/occasional use', 'list_tools lists what is callable right now', and 'subscribe/cancel handle per-MCP billing'. It also distinguishes prompt-library actions (search_prompts/get_prompt/publish_prompt) from MCP/tool actions and notes 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.