chrome-devtools-mcp-mux

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

Annotations provide readOnlyHint=false, indicating this is a mutation tool (creates a screenshot file). The description adds minimal behavioral context beyond this—it doesn't mention side effects like file creation, performance impact, or browser state changes. However, it doesn't contradict annotations, and the action 'take' implies a read operation that produces output, which aligns with the annotation.

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, efficient sentence that front-loads the core action ('take a screenshot') and clarifies the scope ('page or element'). There is no wasted text, and it immediately conveys the tool's essence without redundancy.

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 5 parameters with full schema coverage and readOnlyHint annotation, the description is minimally adequate. However, it lacks output details (no schema provided), doesn't explain behavioral implications like file storage or performance, and offers no usage context. For a mutation tool with multiple parameters, more completeness would be beneficial.

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 100%, with each parameter well-documented in the schema (e.g., format options, quality range, uid usage). The description adds no parameter-specific semantics beyond implying the uid parameter distinguishes page vs. element screenshots. This meets the baseline of 3 since the schema carries the full burden.

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 ('take') and resource ('screenshot of the page or element'), making the purpose immediately understandable. It distinguishes between page and element screenshots, though it doesn't explicitly differentiate from sibling tools like 'take_snapshot' or 'take_memory_snapshot' beyond the obvious screenshot vs. snapshot distinction.

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 provides no guidance on when to use this tool versus alternatives like 'take_snapshot' or 'take_memory_snapshot'. It mentions the page/element distinction but offers no context about appropriate scenarios, prerequisites, or exclusions. The agent must infer usage from the tool name alone.

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