capture_window_tool

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

With no annotations, the description carries full burden. It discloses matching behavior, default max_size, and error handling (returns error listing available windows if no match). It mentions return type as Image. However, it doesn't specify behavior on multiple matches or whether the window is brought to front, leaving minor gaps.

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 concise, well-structured, and front-loaded. It uses a few sentences to cover purpose, usage, parameters, and error behavior. Every sentence adds value with no fluff.

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 2 parameters, no output schema, and no annotations, the description covers the core functionality, parameter details, error handling, and relationship to list_windows. It is complete for an agent to select and invoke the tool correctly.

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 0%, but the description explains both parameters: window_title (full/partial, case-insensitive, matches app names) and max_size (max dimension, default 800). This adds significant meaning beyond the bare schema.

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 'Capture a screenshot of a specific window by its title.' It uses a specific verb and resource, and distinguishes from sibling tools like capture_screen, capture_screen_region, and capture_webpage_tool. It also references list_windows as a complementary tool.

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?

Provides explicit guidance: 'Use list_windows() first to see available windows.' It explains matching behavior (case-insensitive, matches title and app name) and implies when to use this tool vs. siblings. No explicit 'when not to use' but the context is clear.

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