Set media player volume

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

Annotations already declare idempotentHint=true, destructiveHint=false, readOnlyHint=false. The description goes beyond them by naming the underlying service called (media_player.volume_set), the HTTP transport, and the return shape (list of changed states). No auth or rate-limit context, but this is solid added value.

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?

Front-loaded with the core action, then labeled 'Use when' and 'Returns' clauses. Every sentence earns its place; the inline payload documents the exact service invocation.

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?

An output schema exists, so return values needn't be explained (though they are). With 2 fully-documented params, annotations covering the safety profile, and the underlying service named, nothing an agent needs 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%, so the schema already documents both params fully. The description only adds the mapping of 'volume' to the underlying 'volume_level' key, which is minor. Baseline 3 is appropriate.

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+resource ('Set a media player's volume level') and immediately distinguishes itself from sibling volume-stepping operations. An agent can tell this apart from services_media_play_pause / services_media_seek without opening the schema.

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?

Explicit when-to-use clause: 'setting an exact volume rather than stepping it up/down.' This names the alternative behavior pattern, though it does not name a sibling tool by name or give when-not conditions.

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