union_search

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It explicitly states the tool is read-only, requires configuration, and returns clear prompts when improperly configured. It does not elaborate on authentication failures or performance, but the reference to external documentation partly compensates for these gaps.

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 efficiently structured with three sentences that front-load the purpose, then cover prerequisites and behavioral notes. It is concise and to the point, though it could benefit from slight restructuring (e.g., bullet points for configuration) without adding 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?

Given the tool's complexity (cross-library search, configuration requirements, read-only), the description covers the essential aspects: purpose, prerequisites, behavioral traits, and error handling. The presence of an output schema mitigates the need for return value details. It is sufficiently complete for an agent to understand the tool's role and constraints.

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 50%, meaning half of the parameters lack descriptions in the schema. The tool description adds meaningful context: it explains the token parameter as a reader session JWT, outlines configuration dependencies, and clarifies the query parameter's multi-value behavior. This adds value beyond the raw schema, although a full parameter breakdown is absent.

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's purpose as a cross-library union catalog search ('跨馆联盟联合目录检索'), specifying it as an external PROCAT service for OPAC results. This is a specific verb-resource combination that distinguishes it from sibling tools like search_books, which likely target a single library catalogue.

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 prerequisites (requires configuration flags and a JWT token) and declares its read-only nature ('仅只读检索'), clarifying what it does not do (no inter-library loan ordering). While it does not explicitly compare to sibling tools, the context signals infer its specialized use case, and the description mentions an external documentation reference for further detail.

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