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

readOnlyHint=true already tells the agent this is a safe read. The description adds a meaningful scope qualifier — 'currently active and armed' — implying expired, paused, or fired alerts are excluded. Beyond that it discloses nothing about ordering, result limits, or whether phone scoping is required, so with annotations carrying the safety profile a 3 is warranted.

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?

One front-loaded sentence with no filler. The scope qualifier comes before the enumeration, so the most decision-relevant information lands first.

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 read-only, zero-required-parameter list tool with no output schema, the description covers what is returned (three alert categories) and the active-only filter. It falls just short of complete in not clarifying the phone-omitted behavior or default result scope.

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 100% and the single optional phone parameter is fully documented with an E.164 example. The description adds only the phrase 'for the user', which hints at a default to the authenticated account when phone is omitted, but it doesn't state that default explicitly. Baseline 3 applies when the schema does the heavy lifting.

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?

Specific verb plus concrete resource: 'List all currently active and armed' three named alert categories (drop watches, standby threshold alerts, dining reservation stakeouts). An agent can distinguish this from create_watch_alert purely on the list-vs-create axis, though the description never explicitly names a sibling to disambiguate further.

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 'active' and the enumeration of alert types imply the usage context (review what is currently armed), but there is no explicit statement of when to call this versus when to skip it, and no mention of the natural counterpart create_watch_alert or of what to do when the list is empty.

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