Screenshot Window

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the description does not need to repeat safety guarantees. It adds valuable behavioral context by revealing the underlying commands (hyprctl, grim) and the return format (base64 inline), which helps the agent understand execution behavior and output handling without contradicting the annotations.

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 no redundancy. It opens with the core purpose, then specifies implementation details and output format. Every sentence carries meaningful information, achieving maximum conciseness without sacrificing clarity.

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 tool is simple with only two well-documented parameters and no output schema. The description sufficiently explains that the image is returned inline as base64, which is the critical behavioral output. Given the annotations and schema richness, the description covers all necessary aspects for correct invocation and interpretation of results.

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?

Since schema description coverage is 100%, both parameters are thoroughly documented in the input schema. The description restates the window selection logic (title, class, address, focused) but does not add new information beyond the schema. This meets the baseline of 3 for high schema coverage; no extra semantic value is provided.

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 ('Capture a specific window') and the resource (window), while specifying the matching methods (title, class, address, or 'focused'). It distinguishes itself from siblings like screenshot_region and screenshot_fullscreen by focusing on a single window, making the purpose unmistakable.

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 (capturing a specific window) and mentions the technical approach (hyprctl, grim). It does not explicitly contrast with sibling tools (e.g., 'use screenshot_region for arbitrary areas'), but the specificity of 'a specific window' implies its use case over alternatives, earning a 4 rather than a 5.

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