mercari_autocomplete

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

With no annotations, the description carries the full burden. It discloses that results follow the upstream's own relevance order, that an empty list is a normal outcome for obscure input, and that the data is credential-free from an anonymous, login-free session. This goes well beyond a basic function statement and addresses auth and expected-result behaviors.

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 concise sentences, each providing distinct value: purpose, ordering behavior, empty-result normalcy, and data source/credentials. No redundant or filler content.

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?

For a simple one-parameter autocomplete tool with no output schema or annotations, the description covers purpose, behavior, edge cases, and access requirements. It is complete for an agent to select and invoke the tool correctly.

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?

The single parameter 'query' is fully described in the schema as 'Partial keyword to get suggestions for'. The description reiterates 'partial keyword' but does not add significant detail beyond the schema, so the baseline of 3 applies.

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 'Mercari search autocomplete' and clearly states it returns Mercari's own search-suggestion list for a partial keyword in the upstream's relevance order. This specific verb-resource pair ('returns... list') distinguishes it from sibling tools like mercari_search or mercari_item.

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 clearly implies usage for autocomplete/suggestion scenarios via 'partial keyword' and explicitly notes empty lists are a normal outcome, setting expectations. However, it does not name alternative tools or explicitly state when not to use it, so it provides clear context but no exclusions.

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