mercari_search

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

With no annotations provided, the description carries the burden. It discloses credential-free access, anonymous anonymous login-free session, and data source (Mercari's mobile-app API). It also describes the return format (normalized listing summaries plus total matching count), offering useful behavioral context beyond a bare 'search'.

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 sentences, front-loaded with purpose and immediately providing key details about input, output, and data source. No filler.

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 tool is simple with one parameter and no output schema. The description covers what it returns (summaries + count), authentication requirement, and data source, which 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 coverage is 100% and the parameter description 'Free-text keyword search' matches the description's 'free-text keyword'. The description does not add additional meaning beyond the schema, so baseline 3 is appropriate.

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 clearly states the tool 'Searches Mercari listings' with a specific verb and resource, and adds scope via 'free-text keyword'. It distinguishes from sibling tools like mercari_item and mercari_autocomplete by specifying keyword search over listing search.

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 provides clear usage context: search the live resale marketplace by keyword. It doesn't explicitly name alternative tools or state when NOT to use it, but the keyword-search-specific language makes it obvious that other tools handle item details or autocomplete.

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