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

Annotations already declare destructiveHint=false, idempotentHint=true, and openWorldHint=false, so the safety profile is carried structurally. The description adds the immediacy of the effect and the practical retry instruction, but does not say what happens when the conversation is not currently muted (no-op versus error), which is the main behavioral unknown here.

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?

Two short sentences, front-loaded with the action and its UI analogue, followed by the one operational caveat. Nothing repeats the schema or the annotations verbatim, and no sentence could be dropped without loss.

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, annotation-rich mutation with no output schema, the description covers what the tool does, when the effect applies, and the retry contract. The remaining gap is the not-currently-muted case, which is a minor omission rather than a blocking one.

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 coverage is 50%: idempotency_key is fully documented in the schema, while conversation_id has only a uuid pattern. The description reinforces the idempotency contract ('Pass the same idempotency_key when retrying') but adds nothing about conversation_id beyond its self-explanatory name, so it neither compensates for nor worsens the coverage gap.

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 and resource: it ends a conversation's mute, and the clause 'as the inbox's Unmute does' maps the behavior onto a familiar UI action. It implicitly covers the inverse of the snooze_conversation sibling without naming it, so the distinction must be inferred rather than read.

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 word 'now' hints at the use case (immediate unmute versus a scheduled snooze expiry) and the retry guidance tells the agent what to do after a failure. There is no explicit statement of when not to use it, and no sibling tool is named as an alternative, leaving usage context only implied.

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