obs_set_input_settings

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

With no annotations, the description carries the full burden. It discloses the important partial-update behavior ('Pass only the keys you want to change'), implying unspecified settings are preserved. However, it does not mention potential side effects, permissions, or return values, and for a mutation tool this is a moderate gap.

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, front-loaded with the action verb, and provides a crucial usage tip ('Pass only the keys you want to change') without any unnecessary words. It is highly concise and well-structured.

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?

Given the tool's moderate complexity and lack of output schema, the description covers the essential aspects: what it does, how to use it (partial merge), and examples. It does not enumerate all possible settings or mention integration with sibling tools like obs_input_property_items, but for a setter tool this is fairly complete.

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 covers 50% with the 'settings' parameter described as a partial object to merge. The description adds significant semantic value by listing example settings (device, URL, resolution, FPS), helping the agent understand what keys to pass. The inputName parameter remains underdocumented, but its meaning is clear from context.

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 clearly states the tool's purpose with a specific verb ('Change settings') and resource ('an input'), and provides concrete examples like swapping a webcam's device or changing a media source URL. This clearly distinguishes it from sibling tools like obs_get_input_settings (read) and obs_create_input (create).

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?

Usage is implied: 'Change settings on an input' indicates this is for modifying existing inputs. However, it does not explicitly state when to use this tool versus alternatives (e.g., obs_get_input_settings for reading, obs_create_input for creation) or provide exclusion criteria, so guidance is implied but not explicit.

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