obs_press_input_button

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

No annotations are provided, so the description carries the full burden—and it excels. Discloses side effects (press is visible on stream, toggling 'activate' drops camera to black), reversible behavior (toggles both directions), success semantics ('clean result means the button was pressed, not that the thing you wanted happened'), and OBS's caching behavior. Also explains that property_items returns 'The property found is not a list' to confirm existence.

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?

Long (three paragraphs with a bulleted list) but every sentence earns its place—the tool has genuine operational subtleties. Well-structured: core purpose → rationale → two canonical use cases → cautions → discoverability. Front-loads the purpose in the first sentence. Slightly verbose given the sibling tool listing, but the density of actionable information justifies the length.

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 tool with no output schema and no annotations, this description addresses every critical aspect: what it does, why it exists, exact ids for the two real use cases, side effects on live streams, success semantics, and the limitation of property_items. This is not just complete—it teaches the agent how to work around OBS's API limitations.

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%, setting baseline at 3. The description adds real value beyond the schema: propertyName is elaborated with the exact internal ids ('refreshnocache' not 'refresh'), the bidirectional 'activate' behavior, and the note that asking for a non-existent id returns an error. inputName is linked to obs_list_inputs. This exceeds the baseline but doesn't provide per-parameter syntax detail for every edge case.

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 'Press a button inside a source's Properties dialog'—a specific verb and resource. Clearly distinguishes from siblings by explaining OBS exposes actions only as buttons, and explicitly contrasts with obs_set_input_settings (which writes settings, not buttons) and obs_input_property_items (which only enumerates dropdowns).

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?

Provides extensive when-to-use guidance: two concrete use cases with exact ids ('refreshnocache' on browser_source, 'activate' on dshow_input), when not to use (check which scene is live first to avoid dropping a working camera), and how to verify before pressing (via obs_input_property_items error messages). Explicitly names the alternative for verification (obs_screenshot).

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