get_screen_image

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It adds the base64 encoding format, which is useful, and the 'Get' verb implies a read-only operation. However, it does not mention potential errors, permissions, or that no screen is modified, leaving some behavioral aspects undisclosed.

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, focused sentence that immediately states the tool's purpose and output format. There is no fluff or redundant information, ensuring the agent can quickly parse the key functionality.

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 simple read-only screenshot tool, the description is largely complete: it specifies the return format (base64 image) and the action. It lacks details on edge cases like invalid IDs or image format specifics, but given the tool's simplicity and the schema covering required parameters, it is sufficiently complete.

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?

The input schema has 100% coverage for its two parameters, but the descriptions 'Screen ID' and 'Project ID' are minimal. The tool description does not add any contextual meaning to the parameters, so it does not exceed the baseline for schemas with high coverage.

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 verb 'Get' and the resource 'a screenshot of a screen', with the output format 'as base64-encoded image'. This distinguishes it from sibling tools like get_screen_html (HTML content) and generate_screen (creation), 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 does not provide any guidance on when to use this tool versus alternatives. It lacks explicit exclusions, prerequisites, or context such as 'use this when a visual screenshot is needed' or 'prefer get_screen_html for source code'. The usage is only implied by the tool's name and description.

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