chrome-devtools-mcp-mux

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

Annotations indicate readOnlyHint=false, which aligns with the description's implication of a write operation (typing text). The description adds context about the prerequisite (previously focused input) and the optional submitKey behavior, but doesn't detail side effects like rate limits or error conditions. With annotations covering the safety profile, this meets the baseline for adding some 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?

The description is a single, efficient sentence that front-loads the core action ('type text using keyboard') and includes essential context ('into a previously focused input'). There is no wasted verbiage, and every word contributes to understanding the tool's purpose and usage.

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 moderate complexity (interactive input simulation), the description is complete enough for basic use, covering the action, target, and implicit prerequisite. However, it lacks details on output or error handling, and with no output schema, some gaps remain. It's adequate but not exhaustive for all edge cases.

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%, so the schema fully documents both parameters (text and submitKey). The description doesn't add any parameter-specific details beyond what the schema provides, such as examples or constraints. According to the rules, with high schema coverage, the baseline is 3 even without param info in the description.

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 ('type text using keyboard') and the target ('into a previously focused input'), distinguishing it from sibling tools like 'fill' or 'press_key' which have different interaction patterns. It precisely communicates the verb+resource combination without redundancy.

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 clear context by specifying 'into a previously focused input,' which implicitly guides when to use this tool (after focusing an input) versus alternatives like 'fill' (which might not require prior focus). However, it doesn't explicitly state when-not-to-use or name alternative tools, keeping it at a 4.

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