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

Annotations already declare readOnlyHint=false and destructiveHint=false, so safety framing is covered; the description adds genuinely new behavior with "props werden zusammengeführt", telling the agent that prop updates merge rather than replace. It still omits what happens on conflicting flags (send_to_back vs bring_to_front) or whether an unknown widget_id errors or no-ops.

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?

A single compact sentence with zero filler, and the mutation scope is front-loaded ahead of any caveat. Nothing in it is redundant with the title or name in a wasteful way.

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 7-parameter mutation tool with a nested position object, no output schema and only 43% schema coverage, the description is too thin: the z-ordering flags, the board_id fallback interaction and error behavior on a missing widget are never addressed. The merge note is helpful but not enough to make the definition self-sufficient.

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 description coverage is only 43%, and two parameters (send_to_back, bring_to_front) have no description in either the schema or the tool description, so the agent must guess their semantics and interaction. The description only restates props merging and position/size, both of which the schema already explains in more detail.

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 states a specific verb ("Ändert") and resource ("Widget") plus the two aspects it can change (settings/props and position/size), so an agent knows exactly what the call mutates. It does not differentiate itself from near-siblings such as add_widget, remove_widget or widget_action, which leaves some routing ambiguity.

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?

There is no statement of when to use this instead of add_widget, remove_widget or widget_action, and no prerequisites (e.g. that the widget must already exist, or that a board context is needed). Usage is only implied by the word "ändern".

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