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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), yet the description still adds real behavioral context: 'waitlist-only today', 'early USD prices that are subject to change', and 'No network calls'. Those tell the agent the data is a static snapshot that may go stale and requires no external fetch.

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?

Content is front-loaded with the subject ('Facts about PriceMoved...') and the parenthetical list efficiently packs the payload inventory rather than sprawling. The single dense sentence is slightly overloaded, and the trailing API-endpoint reference is marginal, but nothing is truly wasted.

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?

An output schema is present, so the description need not explain return values, and it duly focuses on scope and staleness caveats. For a zero-parameter, read-only info tool it is close to complete; the only omission is any hint about refresh/caching semantics beyond 'subject to change'.

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 tool takes zero parameters, so per the rubric the baseline is 4. The description correctly adds nothing about arguments and instead spends its words on payload contents, which is the right allocation.

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 names the resource precisely and enumerates its payload (current availability, planned Free/Starter/Pro plans with page counts, check intervals, Slack, history, early USD prices, crawler user agent, policy links). That is far more specific than the title 'Product info'. It does not explicitly differentiate itself from the sibling robots_check, but the subject matter is self-evidently distinct.

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 clause 'Same data as GET /api/product' plus 'No network calls' implies this is a static-facts tool an agent should reach for when it needs plan/pricing details rather than live data. There is no explicit when-to-use or when-not-to-use statement and no alternative is named, so usage is only implied.

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