search_era

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

There are no annotations, so the description carries the burden. It discloses that the tool returns era metadata fields and mentions acceptable country values, but it does not explain match behavior (exact vs substring), how multiple filters combine, what happens when no arguments are provided, or any result limits.

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 well structured: purpose first, then return fields, then parameter details. The Args section somewhat repeats the schema property names, but it earns its place by adding examples and allowed values, so the length is justified.

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 return values do not need to be described in depth. However, the tool has three optional, nullable parameters and no required fields, yet the description never states whether at least one filter is expected or how omitted filters behave. It is adequate for simple lookups but leaves important invocation semantics unspecified.

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 schema has 0% description coverage, so the description must compensate. It does so by listing each parameter with concrete examples for name (e.g. '崇禎', '康熙') and explicit allowed values for country (chinese, japanese, korean, vietnamese). It does not clarify whether name/dynasty match exactly or partially, but it adds meaningful semantic detail.

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 for era (年號) metadata by name, dynasty, or country.' It clearly scopes the tool to era metadata lookup and distinguishes it from the sibling date-conversion tools, which have different purposes.

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 for when the tool is appropriate: when you need era metadata such as era name, dynasty, emperor, date range, or JDN range. It does not explicitly name alternatives or exclusions, but the sibling tools are clearly date converters, so the use case is reasonably distinct.

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