select_agent

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

With no annotations, the description carries full burden. It discloses that the active agent receives voice/outgoing requests, that 'exclusive' mode blocks other agents' window/settings changes while still allowing reads and screenshots, and how to clear the selection. This is rich, behavior-specific 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?

Three sentences with front-loaded purpose, followed by necessary operational details. Every sentence earns its place; no fluff or repetition of the schema.

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 two-parameter tool with no output schema and no annotations, the description covers all parameter states, side effects, and integration with get_state. It is complete enough for an agent to select or clear an active agent correctly.

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 already provides 100% coverage with descriptions for both parameters. The tool description adds value by explaining the consequence of 'exclusive' beyond the schema's phrasing and by pointing to get_state's 'agents' as the source for names, yielding a clearer semantic model.

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 opening sentence 'Make an agent the user's active one in Plonk' uses a specific verb and resource, clearly distinguishing it from sibling tools like workspace or screenshot utilities. The rest of the description reinforces scope by defining the active agent's role in the app.

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 explicitly explains parameter variations (omit 'name', pass empty string, pass a valid agent) and directs users to get_state for valid agent names. It does not explicitly name alternative tools, but the behavior is distinct enough that no exclusions are necessary.

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