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

Beyond the minimal annotations, the description discloses the important side effect that music pauses and resumes, and it adds the rate limit ('at least 8 seconds apart') and language default behavior. This is valuable behavioral context for an agent.

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 compact sentences deliver the core action, constraints, and language behavior with no filler. The most important information is front-loaded.

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?

Together with a well-described schema, the description covers the target, the behavior, the limits, and optional language handling. Nothing essential is missing for correct invocation.

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 documents room, text, and volume well. The description adds meaning for the otherwise undocumented language parameter by listing allowed values and explaining the fallback to the home's preference, plus the multi-item text behavior.

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 a specific verb ('Speaks') and resource ('a room's Sonos speaker using text-to-speech'), making the tool's function unmistakable and distinct from sibling playback and volume tools.

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 gives concrete usage constraints: up to 300 characters, at least 8 seconds apart, support for multiple items, and language fallback. It does not explicitly name alternatives or exclusions, but the TTS use case is unambiguous.

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