Leapfrog MCP

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

No annotations provided, so description carries full burden. Discloses return value ('Returns a snapshot') and special index behavior (-1 for most recent). Deducted one point for not mentioning error behavior (e.g., invalid index) or loading states.

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?

Two sentences, zero waste. First sentence establishes core action; second delivers critical usage hint (-1/popups) and return value disclosure. Perfect information density.

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?

Compensates for missing output schema by explicitly stating it 'Returns a snapshot of the newly active tab.' Given simple 2-parameter structure with 100% schema coverage, description is adequately complete. Minor gap: no error handling documentation.

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 coverage is 100%, so baseline is 3. Description adds 'useful for popups' context for tabIndex and reinforces the index concept, but doesn't add syntax/format details beyond the schema.

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?

Clear specific verb ('Switch') + resource ('tab') with scope ('by index'). Implicitly distinguishes from siblings: vs tab_close (closes), vs tabs_list (lists), vs navigate (loads 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?

Provides specific positive guidance: 'Use -1... (useful for popups)' indicating when to use the special index value. Lacks explicit 'when not to use' or named alternatives, but the popup use case is valuable contextual guidance.

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