Make a tab

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

Annotations already declare this as a non-destructive, non-idempotent write, so the safety profile is covered. The description adds genuinely new behavioral context: it returns the canvas id and that add_component consumes it as 'canvas', which is the key chaining detail for a creator tool with no output schema.

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?

Three short sentences, zero waste: identity first, usage conditions second, return value and chaining third. Every sentence earns its place and nothing is buried.

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 one-parameter creator tool with annotations covering the safety profile and no output schema, this is complete: it says what it makes, when to make it, and what it returns and how that return is consumed downstream.

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% and the single parameter's description already specifies the naming convention ('in the person's words, one or two of them: Work, Garden, Rome'). The description adds nothing beyond that, so the baseline of 3 applies.

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?

States a specific verb and resource ('Add a tab: a new canvas beside Home with blocks of its own'), and the phrase 'beside Home' plus 'a new canvas' scopes it clearly against add_component, which adds into an existing canvas. An agent can distinguish it from siblings without opening the schema.

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?

Gives explicit triggering conditions: 'when the person asks for a separate page or tab, or when what they want does not belong with what is already on the canvas.' This implies the alternative (add_component for existing content) but does not name it as an exclusion, so it falls just 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.