browser_blur

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

With no annotations, the description carries the full behavioral burden. It does disclose the useful default (falls back to document.activeElement), but says nothing about whether blur events are dispatched, what happens if the selector matches nothing, whether a tab_id is required, or what the result looks like.

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?

A single tight sentence, front-loaded with the action and immediately qualifying the default target. Nothing is wasted, though the extreme brevity leaves the definition under-specified rather than merely concise.

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 two-parameter tool with zero schema description coverage, no annotations, and no output schema, the description leaves key gaps: tab_id semantics are undocumented and no return or error behavior is described. The active-element default is the only real completeness win.

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 explains selector semantics well, including the default when omitted, but leaves tab_id completely unexplained, so only one of two parameters gains meaning from the description.

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?

States a specific verb ('blur') and resource ('an element'), and adds the default target (document.activeElement) when no selector is given. The sibling browser_focus is the natural counterpart, but the description never names it or draws the contrast, so differentiation is left implicit.

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?

There is no when-to-use guidance: no mention of when blurring is appropriate versus focus-related siblings like browser_focus, and no prerequisites or context. The only guidance is the implicit 'omit selector to blur the active element.'

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