update_block

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

This is a standout feature. It discloses a non-obvious behavioral quirk: DAKboard uses non-linear per-block coordinate scaling, that API coordinates don't map 1:1 to pixels, and that updating permanently changes the scaling factor. Even with no annotations, this fully warns the agent about side effects and required coordinate conversion, going far beyond a typical update description.

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 sentences deliver maximum critical information: what the tool does and the non-obvious coordinate scaling warning with a recommended prerequisite. No filler, no repetition of schema details. Every word earns its place.

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 mutation tool with no annotations and no output schema, this description is nearly complete. It covers the essential action, the critical coordinate caveat, and the prerequisite visualization step. It does not mention return values or error conditions, but given the strong warning and clear input guidance, it fills most of the context 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?

The schema has 100% parameter coverage, so each parameter is individually described. The description adds crucial cross-parameter semantics by explaining that coordinate values (x, y, w, h) must be specified in rendered pixel values at 1920x1080 design resolution, which is not stated in any single parameter's schema description. This transforms the coordinate parameters from ambiguous into actionable.

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 clearly states the tool updates a block on a DAKboard screen and lists the key attributes (position, size, content, visibility). It distinguishes itself from siblings like get_block and list_blocks by its explicit verb 'Update' and resource 'block'.

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?

The description provides explicit pre-usage guidance: 'Use visualize_screen_layout with screen_uuid first to see the actual layout before making changes.' This gives a clear recommended precursor and warns against blind updates, though it does not explicitly say when not to use the tool or mention alternatives like create/delete operations.

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