Screenshot

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

Discloses that screenshots survive session errors, but lacks details on output, asynchronous behavior, or error handling. With no annotations, the description provides minimal behavioral context.

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?

Single sentence, clear and front-loaded with the main purpose, no extraneous text.

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 core purpose and persistence, but omits details on output format, directory location, and integration with evidence session siblings.

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?

Does not add meaning beyond the input schema; the description repeats the tool's action but doesn't explain parameters like sessionId or how name affects filenames.

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 'takes a screenshot' and specifies it saves to an evidence directory for persistence, distinguishing it from sibling tools that perform actions like clicking or navigating.

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 explicit guidance on when to use this tool versus alternatives; only implies usage for capturing evidence without contrast to other tools.

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