pixera_set_live_input

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

With no annotations, the description carries the full behavioral burden and does disclose the important non-obvious dual-mode behavior (list vs. set depending on mode_index). It says nothing about permissions, whether (de)activation is reversible, or side effects on running streams, and it avoids explaining returns — partly excusable since an output schema exists.

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 with zero filler. The primary write behavior is front-loaded and the caveat about listing follows immediately after, which is exactly the ordering an agent needs.

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?

Return values are covered by the output schema, so the description isn't obliged to explain them. But for a 4-parameter mutation tool with no annotations and 0% schema coverage, omitting any guidance on the required folder/resource identifiers leaves the definition thinner than the tool's complexity warrants.

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, and it only partially does: it gives real meaning to mode_index (absence triggers list mode) and implies activate's effect. The two required parameters, folder_name_path and resource_name, are never explained — no path syntax or lookup guidance — leaving a significant documentation hole.

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 names a specific verb and resource — 'Set the stream mode of an existing Live Input resource and (de)activate its streams' — so an agent knows exactly what is being mutated. It also surfaces the secondary list-only behavior. It does not, however, differentiate itself from any named sibling (none of which appear to be live-input specific).

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 conditional 'Without mode_index, only lists the available modes' tells the agent that this tool doubles as a discovery call, which is genuinely useful routing information. But it never states when to prefer this over alternatives such as pixera_get_param or pixera_list_resources, so usage is only implied.

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