verify_element

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

With no annotations, the description carries the full burden for behavioral disclosure. It clearly states two critical behaviors: it never raises on not-found or text mismatch, and it returns a structured boolean result. This is valuable and goes beyond the input schema by clarifying error handling and outcome type.

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?

The description is exceptionally concise: two sentences that front-load the primary purpose and immediately add a crucial behavioral note. Every word earns its place, and there is no redundancy.

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?

The output schema exists, so return values are covered. The description covers the core purpose and the non-raising behavior, which is the key contextual information for an assertion tool. It slightly lacks detail on edge cases like timing or off-screen elements, but for this simple tool it is largely 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 description coverage is 100%, so the input schema fully documents all three parameters. The description itself adds no parameter-specific details, but the baseline score of 3 is appropriate since the schema handles the heavy lifting.

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's function with a specific verb ('Assert') and resource ('semantic target') scoped to the current screen. It also implies differentiation from siblings by emphasizing the boolean, non-raising result, though it does not explicitly name alternative tools.

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 clear context for when to use this tool: when the model needs to branch on existence or text mismatch without exceptions. It does not explicitly list exclusions or alternative tools, but the guidance is sufficient for selecting this tool over siblings like locate or wait_for.

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