Change a block

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

Annotations declare the write/idempotent/non-destructive profile, so the bar is lower. The description adds a genuinely important semantic not in annotations: props are fully replaced, not merged ('send them all'), which is the key gotcha for correct invocation. It doesn't cover permissions or return behavior, but the replacement disclosure is real value.

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?

Two tight sentences, front-loaded with the verb and target, followed immediately by the critical replacement caveat. No wasted words.

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?

A 9-parameter mutation tool with no output schema needs more, but annotations cover the safety profile and the enums are self-describing. The description still omits any mention of size, tone, frame, canvas, or region, so it is adequate rather than complete.

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 56%, so the schema handles roughly half the parameters. The description only maps to props, width (span), and order (position), leaving size, tone, frame, canvas, and region entirely to the schema. Baseline 3 for partial coverage with marginal added meaning.

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 ('Change') and resource ('a block already on the canvas'), then enumerates the changeable aspects (props, width, order). The 'already on the canvas' scoping distinguishes it from add_component/remove_component without naming them explicitly.

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?

Usage is implied by 'already on the canvas,' which signals this is for modifying existing blocks rather than adding or removing them. However, it never explicitly states when to use this vs add_component, arrange_canvas, or propose_change.

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