Screenshot

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

Discloses return format (inline base64) and optional disk saving, but does not mention file overwrite behavior, potential failure modes, or interaction with parameters like fullPage/selector. With no annotations, more behavioral detail would be beneficial.

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?

Two sentences, concise and to the point. Every word contributes, though a bit more structure could improve readability.

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?

Covers basic functionality and return format, but lacks details on error handling, file saving behavior (e.g., overwrite, format), and edge cases. With 4 parameters and no output schema, more completeness is warranted.

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 100%, so baseline 3. Description adds minimal value by restating savePath's optionality. No additional meaning for fullPage or selector beyond the schema descriptions.

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?

Description clearly states the tool captures a screenshot and returns it as base64. The verb 'Capture' and resource 'screenshot of the current page' are specific. While it does not explicitly distinguish from siblings like 'snapshot' or 'extract', the action is distinct enough.

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?

No guidance on when to use this tool versus alternatives such as 'snapshot' or 'extract'. The description lacks context about prerequisites, typical use cases, or when not to use it.

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