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

With no annotations, the description carries the full burden of behavioral disclosure, but it only states the surface function. It does not explain how the tool behaves (e.g., whether it fetches the current page URL, opens a new view, or requires an active tab). The parenthetical 'Browser-based tool' adds minimal context but no operational detail.

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 sentence with a short parenthetical, making it extremely concise and front-loaded. It immediately states the primary action and scope without any fluff. Every word contributes to clarity, earning 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?

The description is inadequate for understanding the tool's complete context. It does not state how the tool obtains the link to preview, what output the agent should expect, or any required browser conditions. For a tool with no input parameters, the description should clarify that it operates on the current browser context or a prior provided URL, but this is missing.

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 has zero parameters, and the schema description coverage is 100% (trivially). Per the baseline rule, with 0 parameters, the baseline is 4. The description merely restates the purpose without adding parameter information, which is acceptable since there are no parameters to document.

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 function: 'Preview how links appear when shared on social media.' The verb 'Preview' and resource 'links shared on social media' are specific and unambiguous. This distinguishes it from siblings like thumbnail-ctr-predictor or meta-description-generator, which have different purposes.

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 does not mention any prerequisites, use cases, or exclusions. The phrase '(Browser-based tool)' hints at operational context but not usage conditions, leaving the agent without clear direction on selecting it over other tools.

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