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

With no annotations provided, the description fully discloses behavior: token cost, region cropping, max_side downsampling, inline=false behavior (file path instead of image), non-overwrite error, and automatic path retention (only last 5 images). These are all behavioral traits an agent needs to know and are not derivable from the schema.

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 dense paragraph that front-loads the critical caution ('default not to use') before diving into parameters. Every sentence adds value, but the length is slightly high; still, given the complexity of 4 parameters and the need for behavioral context, it remains well-structured and efficient.

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 tool with 4 parameters, no annotations, and no output schema, the description covers usage context, parameter semantics, and behavioral constraints thoroughly. An agent has everything needed to decide when and how to call it correctly, including edge cases like file overwrite and auto-path cleanup.

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%, so the description must explain each parameter. It does: inline (return image vs. file path), region (crop area), max_side (downsample long side, default 1280 to save tokens), save_path (specify location, with overwrite and retention warnings). This adds substantial meaning beyond the schema's type/default info.

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's function (take a screenshot) and explicitly positions it as a fallback tool for cases where element trees are unavailable. It distinguishes itself from siblings like get_ui_tree and find_element by naming them and specifying when they fail, making the purpose unambiguous.

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 gives explicit when-to-use (no element tree, self-drawn controls, games, video, remote desktop) and when-not-to-use (default, prefer get_ui_tree + click). It also mentions the alternative tool directly, leaving no ambiguity about the decision process.

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