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

The annotations already declare readOnlyHint=true and idempotentHint=true, so the safety profile is covered. The description goes beyond this by warning about the metric catalogue being the only source of units, adding the actionable caution that a threshold in the wrong unit 'silently never fires.' This is valuable behavioral context that annotations alone do not provide.

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 compact and front-loaded, first describing the tool's output, then adding a meaningful warning. Every sentence earns its place; the language is direct and avoids filler. It reads well for an agent scanning tool descriptions.

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?

The description fully covers the tool's purpose, the scope of the single parameter, the key output elements, and a non-obvious pitfall. With an output schema present, the description does not need to detail return structure. Nothing essential is missing for selecting and invoking this tool correctly.

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?

The schema already documents the single 'mcp' parameter with coverage at 100%, including case-insensitive matching and a pointer to list_mcps. The description adds context that alerts are scoped to 'one MCP' and that the metric catalogue is also returned, but this is not essential parameter-level detail. The baseline of 3 applies because 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?

The description names a specific resource ('alert rule') and states exactly what is returned: the sentence, last fired time, frequency, and channels. It also clearly distinguishes itself from the sibling tool list_alert_firings by describing the alert rules themselves rather than the firing history.

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 description gives explicit usage context: 'Read this before creating a rule.' This tells the agent when the tool is important. It does not explicitly name alternative tools or state when not to use it, but the guidance about the metric catalogue is a strong, clear signal for when this tool is necessary.

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