is_element_displayed

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

Annotations already provide readOnlyHint=true, so description's behavioral burden is lower. Description adds that it checks on-screen visibility (not just existence), which is useful, but doesn't clarify if hidden/zero-size elements return false or error.

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?

Single sentence conveys complete purpose. No filler, no repetition of schema details. Perfectly concise.

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?

Given single parameter, full schema coverage, readOnlyHint, and no output schema, description is adequate. Could mention return type (boolean) since no output schema, but omission is minor.

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 has full description for elementId, so baseline is 3. Description reinforces that the elementId comes from find_element, adding context on tool chaining. This justifies a 4.

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?

Clearly states it checks UI element visibility on screen. Specifies 'not off-screen' to disambiguate from general display checks. Distinguishes from sibling tools like is_element_enabled or is_element_selected.

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?

Implies use for verifying visibility before interacting, but no explicit when-to-use or when-not-to-use guidance. No mention of alternatives among siblings like is_element_enabled or is_element_selected.

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