get_course_thread

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

With no annotations, the description must disclose behavior itself. It clearly states it is a read operation ('Read a thread') and mentions the return content ('Returns full content, comments, and answers'). This is sufficient for a simple get tool, though it does not cover edge cases like auth requirements or error handling, which are not expected to be exhaustive here.

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 two concise sentences plus a structured args list. The first sentence front-loads the core purpose, and each part adds value (usage guidance, parameter explanations) without 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?

The tool has an output schema, so return values are presumably covered by that. The description covers the parameters and use case adequately, and the low complexity of a read-only get operation means no additional explanation is necessary. It is complete for a tool with these characteristics.

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 0%, so the description fully compensates. For course_id it adds 'use list_courses to find it', and for thread_number it clarifies 'as shown in the UI (e.g. 42 for thread #42)', giving concrete examples and preventing confusion with internal IDs.

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 starts with 'Read a thread by its number as shown in the Ed UI (e.g. #42, #220)', using a specific verb and resource and clearly identifying the unique method (by thread number). This distinguishes it from siblings like get_thread and get_thread_by_url, which likely use different identifiers.

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 explicitly states 'Use this when someone refers to a thread by number', providing clear use-case context. It also instructs to use list_courses to find the course_id. However, it does not explicitly mention alternatives or when not to use this tool, so it falls short of a 5.

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