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

Annotations already indicate this is a mutation (readOnlyHint=false) and non-destructive. The description adds a useful nuance ('Muting keeps playback running') that clarifies the effect beyond the schema. It does not disclose other potential behaviors like error handling or effects on grouped rooms, but given annotations cover the safety profile, this is sufficient.

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?

The description is two short sentences with zero filler. The primary action is front-loaded, and the behavioral detail is the only extra, earning its place.

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 simple tool with two parameters and no output schema, the description plus schema covers the essential information: what it does, how it behaves, and the room parameter is described. The 'muted' parameter is implied, and the default-room nuance is in the schema. It is complete enough for an agent to invoke correctly without additional context.

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 50%: the 'room' parameter is described, but 'muted' has no schema description. The tool description does not compensate by explaining the boolean semantics, though the action phrase 'Mutes or unmutes' implicitly maps true/false. With only partial coverage and no additional parameter context, the description leaves the 'muted' parameter underspecified.

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 states a specific verb (mute/unmute), the resource (a single room), and adds a key behavioral detail (muting keeps playback running). This clearly distinguishes it from siblings like adjust_volume or toggle_play_pause.

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 purpose is clear enough to imply when to use it, but the description offers no explicit guidance on when not to use it or comparisons to alternatives. For instance, it doesn't mention that volume control is separate, though the 'keeps playback running' note hints at a distinction.

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