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

With no annotations provided, the description carries the full burden and does well: it discloses that 'value' is null when the attribute is absent, and that it throws only when the target does not resolve. It also notes platform auto-detection. It does not mention behavior on multiple matches or invalid selectors, but the important edge cases are covered for a read-only getter.

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 three sentences with no fluff. It opens with the core purpose, adds more detail on targeting, and covers edge cases. Every sentence carries meaningful information, and the structure is well-organized.

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 tool with no output schema, the description effectively conveys what is returned (an attribute value, with 'value' being null when absent) and how errors behave. It is reasonably complete for an agent to select and call the tool, though it could explicitly state the output structure or mention multiple matches. Overall, it provides enough context for a read-only attribute getter.

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%, so a baseline of 3 is appropriate. The description adds minimal extra parameter meaning beyond the schema, though it does explain the selector/ref distinction and auto-detection, which slightly reinforces but does not fundamentally extend the schema's rich per-parameter descriptions.

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 verb 'Get one attribute' and the resource (element in the device browser page), with specific attribute examples and selection methods (CSS selector or ref). It implicitly distinguishes from siblings like webpage_get_text by focusing on attributes, which is a specific and distinct purpose.

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 when to use this tool (when you need a single attribute) and explains how to target an element (via selector or ref), but it does not explicitly compare with alternatives such as webpage_get_text or webpage_get_dom, nor does it state exclusions or conditional usage. This is functional but not explicit.

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