Set the editor language

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

The description clearly states 'Last writer wins; the change is visible to everyone who has the pad open,' which provides critical behavioral context beyond the annotations. Since annotations declare readOnlyHint: false (confirming mutation) and openWorldHint: true, the description adds value by explaining the real-time, collaborative conflict resolution behavior.

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 sentences with zero wasted words. The first sentence states the tool's core purpose with examples, and the second adds critical collaborative behavior. This is highly efficient.

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?

Given the tool has only 2 parameters with full schema coverage and no output schema, the description is largely complete. It covers purpose, parameter values, and concurrency behavior. It could potentially note that no return value confirmation is provided (useful for confirmation), but overall it is thorough for this scope.

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 coverage is 100%, so the schema already documents both parameters well. The description reinforces the language parameter with examples ('markdown', 'javascript', 'rust') and specifies it uses Monaco IDs, which adds practical guidance beyond the schema pattern. It does not add details about the id parameter beyond what the schema provides.

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 explicitly states the tool sets the syntax-highlighting language of a pad using Monaco language IDs, which is a specific verb+resource combination. It also includes examples of valid language IDs and a behavioral note about visibility, clearly distinguishing it from sibling tools like get_document or set_document.

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 this tool should be used when you want to change the syntax highlighting language for collaborative editing, and notes that the change is visible to all viewers. However, it does not explicitly state when not to use it (e.g., for read-only access or other document features), nor does it reference sibling tools for context.

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