get_screen_hash

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

No annotations are provided, so the description carries the burden of disclosure. It discloses that the operation is cheap and returns a hash-based fingerprint, conveying read-only-like behavior. However, it doesn't detail edge cases or side effects, but for a simple hash tool this is sufficient.

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 two sentences, with the core purpose front-loaded and the usage case following immediately. Every sentence adds value with 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?

Given the tool's simplicity, the presence of an output schema, and the clear use-case explanation, the description is complete. It doesn't need to explain return values since the output schema exists, and the behavioral context is adequately covered.

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 baseline is 3. The description does not add any clarification about the 'mode' parameter (summary vs full) beyond what the schema already states, leaving the agent without additional semantic guidance.

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 returns a cheap fingerprint of the current screen (a hash of the snapshot), using a specific verb and resource. It also distinguishes itself from get_screen by explicitly noting it avoids refetching the full snapshot.

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?

It explicitly guides the agent to call this before and after an action to detect screen changes, and points out the alternative of not refetching the full snapshot, which implies get_screen as the alternative for full content. This gives clear context on when to use the tool.

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