MCP-Midscene

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

No annotations are provided, so the description carries full burden. It states the tool retrieves tab data, which implies a read-only operation, but doesn't disclose behavioral traits like whether it requires specific browser permissions, if it works across all browser windows, potential rate limits, or what happens if no tabs are open. The description is minimal and lacks important operational 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 purpose ('Retrieves a list of all open browser tabs') and adds valuable specifics ('including their ID, title, and URL'). Every word earns its place with no redundancy or unnecessary elaboration.

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 simplicity (0 parameters, no output schema, no annotations), the description is adequate but could be more complete. It explains what the tool does but lacks details on return format (e.g., list structure, error handling) and operational constraints. For a read-only tool with no complex schema, this is minimally viable but leaves gaps.

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 tool has 0 parameters with 100% schema description coverage, so no parameter documentation is needed. The description appropriately doesn't discuss parameters, focusing instead on what the tool returns. This meets the baseline of 4 for zero-parameter tools.

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 ('Retrieves a list') and resource ('all open browser tabs'), with details on what information is included ('ID, title, and URL'). It distinguishes this read-only listing tool from siblings like 'midscene_set_active_tab' (which modifies tabs) and 'midscene_navigate' (which changes URLs).

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 implies usage for getting tab information, but doesn't explicitly state when to use this tool versus alternatives. For example, it doesn't clarify if this should be used before 'midscene_set_active_tab' to identify target tabs, or if there are other ways to get tab data. No exclusions or specific contexts are mentioned.

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