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

Annotations already establish readOnly, non-destructive, and open-world behavior, so the bar is lower. The description still adds real value: it clarifies that nothing is created server-side, that the user completes the action in the app, and that target_price is only a draft in the market currency. It omits auth or rate-limit context, but openWorldHint covers the external nature.

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?

Three sentences, front-loaded with the purpose before the behavioral caveat. The second sentence partly restates the read-only annotation, but it earns its place by explicitly ruling out creation. No filler or unnecessary repetition.

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 an output schema present, the description need not explain return values, and annotations cover the safety profile. For a five-parameter tool, the description covers the core behavior and the one non-obvious parameter. Minor gaps remain around action-specific parameter applicability and error handling.

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?

Schema coverage is only 40%, but the description compensates for the most ambiguous field by defining target_price as an optional draft in the market currency. The action values are restated in prose, while set_id is left to the schema as self-evident. It does not clarify whether target_price is meaningful for the wishlist action or what happens if supplied with action=wishlist.

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 opens with a precise verb and resource: get the existing app link and steps for setting a price alert or saving to a watchlist. That is specific enough to separate it from every sibling, which are all data-retrieval or comparison tools rather than app handoffs.

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?

Usage is implied by naming the two supported actions (price alert, watchlist), and the 'handoff' framing tells the agent this is not a data query. However, there is no explicit when-not-to-use guidance, no named alternatives, and no statement about prerequisites such as requiring a known set_id or market.

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