tv_state

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

With no annotations, the description carries the transparency burden. It explicitly discloses that the tool is read-only and returns a structured snapshot with specific fields. This is useful behavioral context beyond what the schema provides, though it does not discuss error conditions or prerequisites like whether the app must be running.

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 two sentences long and front-loaded: the first sentence lists the snapshot contents, the second clarifies read-only usage. No filler words or redundant information; every phrase contributes meaning.

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 tool has no output schema, so the description's enumeration of returned fields (url, title, visible scenes, focused element, popups, counts) provides essential return-value information. It is complete for a simple read-only snapshot tool, though it could mention prerequisites or error scenarios for full completeness.

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 schema description coverage is 100% for the single optional 'device' parameter, so the schema fully explains it. The description adds no parameter-specific information, but the baseline of 3 is appropriate because the schema already documents the parameter adequately.

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 ('snapshot') and resource ('the app'), and enumerates exact contents (url, title, visible scenes, focused element, popups, counts). It clearly distinguishes from sibling tv_video_state by focusing on app state, and the read-only qualifier further differentiates it from mutation tools.

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 clear usage context: 'use it to assert a step without pressing anything.' This tells the agent when to use it (for assertions) and when not (when interaction is needed). However, it does not explicitly name alternative tools or provide exclusion scenarios, so it falls slightly short of a 5.

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