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

No annotations are provided, so the description carries full responsibility for disclosing behavior. It mentions the action of checking title and description length and the word 'Preview' suggests a non-destructive simulation, but it does not state whether the tool fetches live data from the URL, how the preview is rendered, or any side effects or limitations.

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, front-loaded with the primary action. Every word is necessary and there is no redundant information. The description is appropriately sized for the tool's simplicity.

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?

For a simple tool with three optional parameters, the description gives a clear overview of what the tool does. However, it lacks detail about the output (what the preview looks like) and the relationship between 'url' and the title/description parameters, which could leave an agent unsure about how to invoke it correctly. Nevertheless, the overall purpose is understandable and the schema fills most 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 input schema provides 100% coverage of parameter descriptions, so the baseline is 3. The description adds no additional meaning beyond the schema; it merely mentions title and description length without explaining how the 'url' parameter factors into the preview or how the parameters interact.

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 uses the specific verb 'Preview' with the resource 'your page in Google search results', and adds the secondary function of checking title and description length. This clearly distinguishes it from sibling tools like pagespeed or keyword_research, which focus on different aspects of SEO.

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 by stating what the tool does, but it does not explicitly mention when to use it over alternatives or provide any exclusions. There is no reference to sibling tools or conditions under which this tool is preferred, leaving the agent to infer usage from context.

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