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

The description goes beyond the annotations (readOnlyHint, openWorldHint, idempotentHint, destructiveHint=false) by adding context: 'Public — no auth required' and the x402-gated nature of the premium-briefing URL. It also discloses the tool's composite nature and return components, which is valuable behavioral information.

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 two sentences with no fluff. The first sentence packs the return contents, the second provides usage context and alternatives. Every word earns its place, making it concise and well-structured.

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?

With only one parameter, no output schema, and rich annotations, the description covers the essential context: what the tool returns, when to use it, and that it's public. The explicit enumeration of return components compensates for the lack of an 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?

The schema already provides 100% coverage for the single 'vertical' parameter with a detailed description of valid slugs. The description adds minimal parameter-specific meaning beyond repeating 'single vertical', so a baseline 3 is appropriate.

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 states what the tool does: 'Return everything an agent needs to onboard a listener for a single vertical in one tool call' and explicitly lists the components (top stories, host persona, premium-briefing URL, public RSS feed). It distinguishes itself from sibling tools by describing the one-shot aggregation versus individual calls.

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 usage guidance: 'Use after the agent has decided which vertical to set up' and names the alternative round trip it saves (get_personas, search_articles, get_premium_briefing). This clearly tells the agent when to use this tool instead of others.

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