build_library

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

With no annotations, the description carries the disclosure burden, and it does well: it reveals background execution, one-time/resumable semantics, estimated durations, and library contents. It does not mention authorization requirements or whether a rebuild overwrites existing data, but the core behavioral traits are clearly disclosed.

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 key purpose and monitoring signal are front-loaded, and there is no filler. The mode explanation is dense and encoded in a long parenthetical, but it remains compact and information-rich.

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 single-parameter background setup tool with an output schema, the description covers the essential operational details: one-time nature, resumability, progress via library_status, mode options, duration, and scope. Nothing critical is missing 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?

The schema only defines mode with a default and no description or enum, so the description must compensate. It fully defines the three mode values, the default, and the practical difference between them, giving the agent everything needed to choose correctly.

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 operation: install/build the card library, and distinguishes it from siblings like search_cards and library_status. It also names the concrete modes (download, quick, full), so an agent understands exactly what resource is affected and how.

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 explicit usage context: it is one-time and resumable, progress should be checked via library_status, and the mode choices are explained with tradeoffs (prebuilt vs raw dataset, minutes vs hours). This tells the agent when to use this tool and which mode fits the need.

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