set_library

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

No annotations are provided, so the description carries the full burden of disclosing behavioral traits. It states that it 'opens' a local folder and 'scans' for images, implying a state change, but it does not mention side effects like replacing the current library, required permissions, or whether the scan is recursive. For a tool that mutates the environment state, more disclosure is needed.

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 a single, concise sentence (14 words) that front-loads the primary action and object. There is no redundancy or unnecessary elaboration. Every word contributes to understanding the tool's core purpose.

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 tool with one parameter, no annotations, and no output schema, the description provides a basic understanding. However, it is incomplete in key behavioral aspects: it does not clarify whether setting a new library replaces the previous one, what 'scan' entails (e.g., indexing, supported formats), or any return value. Given its role as a setup operation among image-related tools, more context would help the agent use it 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 input schema has one parameter 'path' with no description. The tool description does not mention the parameter by name, but the phrase 'local folder' directly alludes to the 'path' parameter's meaning. Since schema coverage is 0%, the description adds some semantic value, but it does not specify details such as the path being a directory or whether it must be absolute. It partially compensates for the lack of schema documentation.

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 function: 'Open a local folder as the photo library and scan it for images.' It uses specific verbs (open, scan) and identifies the resource (local folder, photo library). This distinguishes it from sibling tools, which focus on individual images or recipes rather than library-level setup.

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 implies usage context: it sets the library before other operations. However, it does not explicitly state when to use this tool versus alternatives, nor does it mention any exclusions or prerequisites. For instance, it does not say 'use this before list_images' or that setting a new library replaces the existing one. The guidance is implicit rather than explicit.

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