etsy_user_favorite_listing_get

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

Annotations already declare readOnlyHint=true, so the description adds little beyond that. It does not disclose additional behavioral traits such as authentication requirements, rate limits, or what happens when the listing is not in favorites. However, it is consistent with the annotation.

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 a single clear sentence that is front-loaded with the purpose. It could be slightly more informative without losing conciseness, but it avoids unnecessary words.

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 does not mention the return format (e.g., boolean or object), which is critical given the lack of an output schema. The tool is simple, but the description leaves the agent guessing about the response structure.

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 description coverage is 0%, and the description does not provide any meaning for the two parameters (user_id, listing_id). The agent must rely solely on parameter names and types, which may be insufficient for correct invocation.

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 uses a specific verb ('Check') and clearly identifies the resource ('if a specific listing is in a user's favorites'), distinguishing it from sibling tools like 'etsy_user_favorite_listing_add' or 'etsy_user_favorite_listings_list'.

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 implies the tool is for checking existence, but does not explicitly state when to use this tool instead of alternatives like listing or adding favorites. Without explicit guidance, the agent may need to infer from the tool name and context.

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