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 this tool frees memory and should be called after reading chunks, which are useful behavioral traits. However, it lacks details on permissions, side effects (e.g., if the session becomes inaccessible), or error handling, leaving gaps for a mutation tool.

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 very concise with two sentences that are front-loaded and waste no words. Each sentence adds value: the first states the purpose, and the second provides usage guidance.

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 has an output schema (which likely covers return values) and no annotations, the description is moderately complete. It covers purpose and usage but lacks details on parameters, error cases, or dependencies with siblings like 'get_screenshot_chunk', leaving room for improvement in context.

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. It implies 'capture_id' is needed to identify the session but doesn't explain its format or source. The description adds minimal context beyond the schema, resulting in a baseline score due to incomplete parameter documentation.

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 action ('Release') and resource ('screenshot session'), and mentions freeing memory as the outcome. It distinguishes from siblings like 'capture_screenshot' or 'start_screenshot_capture' by focusing on cleanup, but could be more explicit about what a 'screenshot session' entails.

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?

It provides explicit guidance on when to use this tool ('after reading all required chunks'), which helps differentiate it from siblings like 'get_screenshot_chunk'. However, it doesn't specify alternatives or when not to use it, such as if chunks are still needed.

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