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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the bar for additional disclosure is lower. The description adds useful context: no API key, public metadata only, guest-callable, and a 20-query/session cap. However, the 'Price 0.01 USDC/query' line is ambiguous and could be misread as a cost of this tool, conflicting with the 'FREE preview' claim.

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 most important fact is front-loaded ('No API key needed — call this now'), but the description repeats 'free/no key/no payment' multiple times and ends with filler like 'Try one of the sample questions now.' The promotional tone and redundancy keep it from being appropriately concise.

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?

Given the low complexity, zero required parameters, and rich annotations, the essential context is present: auth-free, free, read-only, specific listing, and example questions. Missing are a clear statement of what the response returns and resolution of the 0.01 USDC pricing ambiguity. It is adequate but not fully 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?

Both parameters are fully documented in the schema (100% coverage), so the baseline is 3 even without description support. The sample questions add concrete examples for the question parameter, and the schema already explains slug defaulting. The description does not materially expand parameter semantics beyond those examples.

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 identifies this as a free, no-key preview of the producthuntwatch listing and gives sample questions to try. It distinguishes itself from paid/session-based siblings by emphasizing 'FREE preview — no key, no payment.' It lacks an explicit 'preview a data listing' verb phrase, but the schema description 'Free, guest-callable taste of a listing' reinforces the purpose.

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 says 'No API key needed — call this now' and 'FREE preview — no key, no payment,' making it clear this is the free entry point. It implies use before funded session tools like data_session_query, but it never names alternatives or states when not to use it. The context is strong, but exclusion guidance is missing.

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