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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds the input precondition that a numeric listing id is needed, but discloses nothing about auth, rate limits, or data freshness. Modest added value over annotations.

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?

Two short sentences, front-loaded with the resource and its returned fields, then the input requirement. Efficient with no filler, though quite terse.

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 exists, so the description needn't explain return values, and annotations carry the safety profile. For a single-parameter read tool this is nearly complete; only the lack of routing guidance toward etsy_search leaves a minor gap.

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 0% and the sole 'id' parameter has no description. The description compensates partially by clarifying that the id is the numeric listing id, but this largely restates the parameter name and adds no syntax or format detail beyond 'numeric'. Baseline for a single undocumented param.

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 states a specific resource (Etsy listing detail) and enumerates the fields returned (title, price, images, materials, tags, shop), which clearly distinguishes it from siblings like etsy_search or etsy_shop. It stops short of explicitly naming which sibling to use for discovery versus detail lookup, so it earns a 4 rather than 5.

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?

It states a precondition ('Requires the numeric listing id'), which implies this is a detail-lookup called after obtaining an id. However, it gives no guidance on when to use this versus etsy_search or etsy_shop_listings, and no exclusions. Usage is implied, not explained.

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