Add a URL source

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

Annotations indicate a write operation (readOnlyHint=false) and non-idempotent behavior (idempotentHint=false). The description adds disclosure of auto-detection of YouTube URLs, which is a behavioral trait beyond the annotations. However, it does not mention potential side effects like validation, rate limits, or authentication needs.

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, front-loaded sentence with no unnecessary words. It efficiently conveys the core purpose and a key behavioral note (YouTube auto-detection).

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 three parameters and no output schema, the description covers the main action and a special behavior. However, it lacks details on error scenarios, whether the notebook must exist, and what the tool returns (e.g., source ID). It is mostly complete for the tool's simplicity.

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 three parameters with 33% description coverage (only notebook is described in schema). The description adds meaning for the 'url' parameter (supports web and YouTube) but does not describe the 'title' parameter or elaborate on 'notebook'. It adds some semantic value but relies heavily on the schema for the rest.

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 'Add a web URL or YouTube link as a source.' It uses a specific verb and resource, and distinguishes from sibling tools like 'source_add_text' by focusing on URL-based sources. The mention of auto-detection of YouTube URLs adds specificity.

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 for adding web URLs or YouTube links, but does not explicitly guide when to use this tool over alternatives such as 'source_add_text' for text content. No when-not-to-use or prerequisite conditions are provided.

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