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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, covering the safety profile, so the bar is lower. The description adds useful UI context (opens fullscreen onto a fresh blank page, no arguments), which explains why idempotentHint=false is plausible for a window-opening action, but it never states whether an existing editor is reused, focused, or replaced.

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?

One sentence, front-loaded with the verb and action, with no filler. The colon-heavy phrasing and undefined 'anew' slightly reduce readability, but structurally it is tight.

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 zero-parameter, no-output-schema tool the explanation of the action is present, but with no output schema the description does not say what the agent observes after calling it (state change, returned handle, focus behavior). It is adequate but leaves that gap.

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?

There are zero parameters and the schema is fully self-describing, so the baseline is 4. The description's 'Takes no arguments' is a small but accurate confirmation that adds a little reinforcement.

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?

It states a verb and resource ('Open ... the editor, fullscreen, on a new blank page'), which is more specific than a bare name restatement, but the object 'anew' is never defined and reads as product branding rather than a resource, leaving ambiguity about what exactly is being opened. It gives modifiers (fullscreen, blank page) that help, but it never contrasts with sibling tools like anew_page or anew_read, so the agent must infer the distinction.

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?

No when-to-use guidance and no exclusions are provided. With three siblings (anew_page, anew_read, anew_write) offering overlapping 'anew' concepts, the description should have said when to pick the editor over the page/read/write variants, but it supplies nothing.

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