browser_emulate_media

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

With no annotations, the description carries the full burden, and it does disclose important state semantics beyond the schema ('Omitted parameters are left unchanged; null clears an override'). It still omits whether the override persists across navigations, whether a page must already be loaded, and whether the effect is reversible.

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 tight sentences, front-loaded with the purpose and then the state semantics. No filler; every clause carries information.

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 no-output-schema, no-annotation tool with five optional params, the description covers purpose, an example, and reset semantics adequately. Gaps around persistence and required page state are minor but real.

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 coverage is 100%, so the baseline is 3, but the description adds meaning the schema does not: the null-vs-omitted semantics (null clears, omission leaves unchanged). This is directly parameter-relevant and goes beyond the type-level schema definitions.

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 ('Emulate') and resource ('CSS media features') with a concrete example ('switch between the light and dark color scheme'). The resource is distinct enough from siblings like browser_resize (viewport) that an agent can tell them apart, though the description never names an alternative explicitly.

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 example implies you reach for this tool when you want to test dark/light schemes, so usage is inferable. However there is no explicit when-to-use, no when-not-to-use, and no comparison against related siblings like browser_resize or cloak_set_fingerprint.

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