activate_zone

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

No annotations are provided, so the description carries the full behavioral disclosure burden. It doesn't indicate whether this is a mutating operation (it clearly is), what happens if the zone_id is invalid, whether the change is reversible, whether it requires specific permissions, or what the resulting audio state will be. For a system-routing mutation with zero annotation coverage, this is a significant gap in behavioral context.

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?

A single concise sentence that front-loads the action (Switch) and target (system audio routing). No filler, no repetition, no wasted clauses.

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 single-parameter mutation tool with no annotations and no output schema, the description is adequate for basic invocation but incomplete. It doesn't surface error handling, side effects on other audio routes, or what 'pre-configured zone settings' entail. The 100% schema coverage helps, but a mutation with zero annotations needs more than a one-liner.

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 100% with a single well-described parameter (zone_id, 'Zone identifier to activate'). The description adds minimal meaning beyond the schema, which is appropriate given the schema already documents the parameter fully. Baseline 3 is correct when the schema does the heavy lifting.

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 (Switch) and resource (system audio routing) scoped to a pre-configured zone. This distinguishes it reasonably well from siblings like configure_zone (which configures rather than activates) and set_output_device (which targets a single device, not a saved zone). Clear and specific, though it could more explicitly contrast with configure_zone.

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 implies usage by referencing 'pre-configured zone's settings', suggesting this applies an existing configuration rather than creating one. However, it does not explicitly state when to use this versus configure_zone or list_audio_zones, nor does it mention prerequisites like whether a zone must already be configured. Usage context is implied but not spelled out.

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