ebay_find_completed_items

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

Annotations already declare readOnlyHint=true, and the description adds useful context beyond that: it specifies the Finding API operation, the app-credential requirement (SECURITY-APPNAME / EBAY_CLIENT_ID), that the data is public, and the cleaned fields returned. It does not describe pagination or rate limits, but the read-only annotation lowers the burden and the credential disclosure is valuable.

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 four sentences with the core purpose front-loaded. Each sentence adds distinct value: purpose, API/credential, return fields, and auth sufficiency. There is no filler or tautology, and the length is proportionate to what an agent needs to know.

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?

There is no output schema, but the description compensates by listing the returned item fields explicitly. It also covers credentials and the public-data nature. It does not mention error cases or pagination, but for a read-only search tool with three well-documented parameters, the provided context is sufficient for correct invocation.

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 100%, so the schema already documents keywords, daysBack, and maxResults. The description adds no parameter-level meaning beyond what the schema provides; it focuses on purpose and return shape. Baseline 3 is appropriate because the schema carries the parameter documentation.

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 specific verb and resource: 'Search eBay sold/completed listings for pricing research.' It names the underlying API operation and explicitly identifies this as the sold-comps search tool, distinguishing it from sibling tools like ebay_find_active_items. An agent can immediately tell what this tool does without inspecting the schema.

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 gives clear context: 'Useful for market price research before listing or repricing.' This indicates when an agent should reach for this tool. It does not explicitly name alternatives or exclusion criteria, but the sold/completed scope versus active-listing siblings makes the intended use reasonably unambiguous.

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