SerpMCP

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states the tool performs a search and returns results, but lacks details on rate limits, authentication needs, error handling, or what 'structured image results' entail (though an output schema exists). For a search tool with zero annotation coverage, this is a significant gap in transparency about operational behavior.

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 concise and front-loaded, with two sentences that directly state the tool's function. There's no wasted language, and it efficiently conveys the core purpose. However, it could be slightly more structured by explicitly mentioning key parameters or use cases, which prevents a perfect score.

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 (5 parameters, 1 required), 100% schema coverage, and the presence of an output schema, the description is reasonably complete. It clearly states what the tool does, and the output schema handles return values. The main gap is the lack of usage guidelines relative to siblings, but overall, it provides enough context for basic understanding.

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%, meaning all parameters are well-documented in the input schema itself. The description adds no additional meaning about parameters beyond what the schema provides (e.g., it doesn't explain query formatting or result implications). With high schema coverage, the baseline score is 3, as the description doesn't compensate but also doesn't need to.

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 tool's purpose: 'Search Google Images and get image results' and 'Performs a Google Image search and returns structured image results.' This specifies the verb ('search'), resource ('Google Images'), and outcome ('structured image results'), making it easy to understand. However, it doesn't explicitly differentiate from sibling tools like serp_google_search or serp_google_videos, which is why it doesn't score a 5.

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. It doesn't mention sibling tools like serp_google_search (for general web results) or serp_google_videos, nor does it specify use cases or exclusions (e.g., when image search is preferred over other search types). This lack of contextual guidance leaves the agent to infer usage based on 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.