Screen MCP

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

No annotations are provided, so the description carries the full burden. It discloses that the screenshot is stored 'in a temporary server-side session' and implies a multi-step process, but lacks details on permissions, rate limits, error handling, or what 'temporary' entails. It adds some context but is incomplete for a tool with no annotations.

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 front-loaded with the core purpose in the first sentence, followed by concise usage guidelines. Both sentences earn their place by providing essential workflow context without redundancy, making it efficient and well-structured.

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 the tool's complexity (multi-step flow, 5 parameters with 0% schema coverage, no annotations), the description is incomplete. It explains the workflow well but omits parameter details and behavioral aspects like session management. The presence of an output schema helps, but gaps remain for adequate agent use.

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 compensate for the 5 undocumented parameters. However, it provides no information about any parameters (e.g., what 'monitor_index' or 'chunk_size' mean), failing to add meaning beyond the bare schema. This leaves parameters largely unexplained.

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 specific action ('Capture a screenshot') and resource ('store it in a temporary server-side session'), distinguishing it from siblings like 'capture_screenshot' by specifying it's part of a chunked flow. The purpose is explicit and well-defined.

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 explicitly states when to use this tool ('step 1 of the chunked screenshot flow') and provides a clear sequence of next steps ('get_screenshot_manifest', 'get_screenshot_chunk', 'release_screenshot_capture'), differentiating it from alternatives like 'capture_screenshot' by outlining the workflow.

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