browser_observe

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

With no annotations, the description carries the burden of disclosing behavior. It explains the output shape (numbered, actionable controls), gives an example format, and notes that refs stay stable across observations. It does not cover failure modes, but for a read-only observation tool this is meaningful behavioral 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 compact and front-loaded with the most essential information: what the tool reads, what the output looks like, and how refs should be used. Every sentence earns its place with no redundant wording.

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 one-parameter tool, the description covers the output format and ref stability well. However, it leaves tab selection ambiguous and does not describe what happens when tabId is omitted or invalid. The absence of an output schema makes the lack of explicit return-value details more noticeable, though the example format helps.

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 0%, so the description must compensate. It mentions 'the target tab' but never explicitly explains the tabId parameter, its optionality, or how it is resolved. Given that tabId is not required according to the schema, the missing default behavior is a notable gap.

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 a specific verb and resource: 'Read the target tab as an element table.' It also differentiates itself from siblings by framing the output as actionable controls and referencing a follow-up action ('then act on the refs'), which distinguishes it from browser_act, browser_navigate, and browser_status.

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 gives clear workflow context: read the tab, then act on the returned refs. It does not explicitly name alternatives or exclusion conditions, but the 'read then act' instruction makes the intended position relative to sibling tools reasonably clear.

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