get_thread_by_url

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 does state that the operation is a 'Read' and that it returns content, comments, and answers, which is useful. However, it does not detail authentication requirements, error handling, or edge cases (e.g., invalid URLs, permissions). For a read-only tool, this is adequate but not exhaustive.

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 extremely concise and well-structured. The first sentence states the action, the second gives a clear when-to-use trigger, and the Args section provides parameter details. Every sentence earns its place with no redundancy or fluff.

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 one-parameter read tool, the description is nearly complete. It specifies the input format, the intended use case, and the return value (content, comments, answers). Since an output schema exists, the description does not need to detail the response structure. It lacks only minor details like rate limits or auth scopes, but these are not critical for this simple tool.

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 no description for the 'url' parameter (0% coverage), so the description must compensate. It does so excellently by defining the parameter as 'Full Ed Discussion thread URL' and providing a realistic example. This fully clarifies the expected input format and meaning, leaving no ambiguity.

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 reads a thread from an Ed Discussion URL. It uses a specific verb ('Read') and resource ('thread by URL'), and distinguishes itself from siblings by emphasizing the URL-based retrieval mechanism, which is unique among tools like get_thread or get_course_thread.

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 explicit context for when to use the tool: 'Use this when someone shares a link to a thread.' This is clear and actionable, though it does not explicitly exclude alternative tools or provide a when-not-to-use scenario. The close sibling get_thread likely accepts an ID, so this URL-based tool fills a distinct niche, but the description could have explicitly contrasted them.

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