live_places

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

Annotations already declare readOnlyHint=true, so safety is covered. The description adds genuinely useful context beyond that: the buttons trigger live.select on click in MCP Apps clients and bypass an assistant turn. It does not describe what the tool returns to the model or what happens in clients that don't render apps, which keeps it below 5.

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 front-loaded sentence that leads with what is rendered and then the click behavior. No filler, every clause carries information.

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?

With no output schema and full schema coverage on inputs, the description covers the essential behavioral twist (UI buttons, no assistant turn). Minor gaps remain around fallback behavior in non-App clients and interaction with the mode parameter, but nothing critical is missing.

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% and the nested places object is fully documented in the schema, so the description adds little parameter detail. Its only contribution is loosely tying the click action to select-style behavior, which the schema's mode enum already spells out precisely.

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 concrete verb and resource ('show a list of places as buttons') and explains the interaction payoff (a click calls live.select with no assistant turn), which distinguishes it from live_select and locate. It stops short of naming those siblings explicitly, so the differentiation is implied rather than guaranteed.

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 phrase 'in a client that renders MCP Apps' implicitly scopes when this tool is useful, but there is no explicit when-to-use, when-not-to-use, or alternative (e.g. use live_select directly for non-UI clients). Usage is left to inference.

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