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

Annotations already flag destructiveHint=true, but the description goes well beyond by disclosing two distinct outcomes: an owned alarm is deleted for all joiners and cannot be undone, while a joined alarm is left and still rings for others. It even states that the response indicates which branch occurred, which is behavioral context the annotations cannot convey.

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 core action is front-loaded in the first sentence, and the following sentences each carry distinct behavioral weight (the disable alternative, owner-versus-joiner semantics, return value). It is slightly longer than minimal but no sentence is filler.

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?

There is no output schema, and the description compensates by explaining what the return value distinguishes ('Returns which of the two happened') while covering the destructive, irreversible side effect and the permission-scoped behavior. An agent has everything needed to call and interpret it.

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% with a single required 'id' parameter that the schema already documents. The phrase 'by its id' adds no meaning beyond the structured field, so the baseline score applies.

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 up front ('Deletes an alarm by its id'), and explicitly distinguishes itself from the closest sibling by contrasting deletion with switching off. An agent can separate this from turn_alarm_on_off, update_alarm, and the set_*_alarm tools without opening any 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?

Names the key alternative ('Switching an alarm off instead keeps it'), giving the condition that drives the choice between deleting and disabling. It lacks guidance versus the other mutation siblings (update_alarm, join_alarm) or any explicit prerequisite, but the critical fork is stated.

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