press_key

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

Annotations indicate destructiveHint=false, and the description adds behavioral detail about the returnSnapshot parameter (returns fresh snapshot, renumbers element refs). However, it lacks disclosure of behavior for invalid keys, page load timing, or default return value.

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 a single efficient sentence with examples, no redundancy or fluff. It is front-loaded and 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 simple tool with 2 parameters and no output schema, the description covers basic purpose and one parameter's effect. Missing information includes error handling, page readiness guarantees, and default return value when returnSnapshot is false.

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 50%; only returnSnapshot has a description. The description provides example keys (Enter, Escape, etc.) which adds partial meaning, but does not specify valid formats or constraints for the key parameter beyond the schema's maxLength/minLength.

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 action (press), the resource (current page), and provides specific examples (Enter, Escape, ArrowDown, Control+A). It effectively distinguishes from sibling tools like click or type_text.

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 implies usage for pressing keys but does not explicitly state when to use this tool over alternatives like type_text or click. No exclusions or alternative recommendations are provided.

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