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

Adds useful behavior beyond annotations: coordinateSpace semantics, preserving y and other geometry during horizontal centring, and separation of text alignment from box position. However, despite destructiveHint=true, it does not describe what may be overwritten or mutation consequences; the schema notes overwrite risk, but the tool description itself omits that important behavioral context.

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?

Four front-loaded sentences, each carrying a distinct point: the alignment mechanism, a centring example, the text-versus-box distinction, and a preservation caution. There is no filler and the most important constraint appears first.

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 complex, open-world, destructive tool with no output schema, the description covers the essential calling semantics and preservation behavior. It is less complete on mutation consequences, but the destructive annotation and rich input schema supply much of that missing context.

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 most parameters, but the description adds real meaning with a concrete placement example ({x:0.5}) and explanation of coordinate-space behavior. It does not explain many alias or batch fields, but those are covered by the schema.

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 action (align the target element) and mechanism (explicit placement coordinates in the existing coordinate space), and distinguishes it from text alignment. It does not explicitly contrast with nearby siblings like move_element, resize_element, or rotate_element, so sibling differentiation is partial.

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?

Explains that an instruction alone does not set alignment, gives a concrete print_area centring example, and advises preserving intentional off-centre placement unless the user requests a change. It lacks explicit naming of alternative tools for repositioning, but the usage context and a key when-not condition are clear.

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