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

The description adds rich behavioral context beyond the annotations: invoke runs tools even when not installed, one-off without bloat; returns connect/checkout links under credential/payment conditions; and search/describe flag installation state. These details significantly exceed the minimal hints provided by annotations and disclose important edge-case behaviors.

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 organized, using 'Core flow:' and 'KEY:' markers to highlight essential guidance. It is longer than ideal for a single paragraph, but every sentence carries useful information, making it efficient despite lacking bullet points.

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 covers all major action branches—search, describe, invoke, install, list_tools, subscribe/cancel, report_bug, request_mcp, and the prompt library—with context on when to use each. It omits the 'resume' action and does not describe return value structures, but for a tool with 23 parameters and no output schema, it is quite comprehensive.

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 compensates by explaining the main action values (search, describe, invoke, install) and linking them to parameters like query, mcp_id, tool_id, and arguments. However, it does not explain many secondary parameters (immediate, tier_slug, cancel_reason, etc.), though some are self-explanatory or have enums.

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 the core search→describe→invoke flow, distinguishing it from sibling tools like authenticate or ibama_debitos_consultar, which are unrelated to marketplace operations.

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 explicitly contrasts invoke vs. install: 'Use install only to make an MCP PERMANENT in the active toolkit... prefer invoke for a single/occasional use.' It also differentiates list_tools as listing only callable tools and notes that writes require workspace owner/admin, providing clear when-to-use and when-not-to-use guidance.

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