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

Annotations provide idempotentHint, readOnlyHint, and destructiveHint, but the description adds critical behavior: it never publishes, it returns a review link and connection status, and it requires a signed-in user. It clarifies side effects (creating a draft) and non-actions (not publishing), which is essential context beyond the structured hints. No contradiction with 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?

The description is a single, dense sentence that front-loads the audience ('For a signed-in user') and proceeds logically: input, action, output, and non-action. It is efficient with no wasted words, though it is long. Every clause adds information, so it earns a 4 rather than a 5 due to the length.

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 no output schema, the description must and does explain the return: the review link, whether eBay is connected, and the connect link if not. It covers prerequisites (signed-in user, scan_id from price_item) and clearly states the non-destructive nature. For a creation tool, this is 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?

Schema coverage is 100%, so the baseline is 3. The description adds extra meaning by noting the price defaults to the market price, which clarifies the price parameter's default behavior not fully spelled out in the schema. It also implies title and condition are overrides, aligning with the schema. This goes slightly beyond the schema.

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 clear, specific action: turns a photo scan into an inventory item with a draft eBay listing. It explicitly names the source tool (price_item) and the deliverable (link for review/publish), and adds a key boundary ('It never publishes anything') that distinguishes it from any publishing action. This is specific and unambiguous.

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 a workflow ('from price_item') and a precondition ('For a signed-in user'), but it does not explicitly state when to use this tool versus alternatives or when not to use it. It names no sibling tools as alternatives, so an agent must infer the context from the mention of price_item. This is adequate but not explicit.

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