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

Annotations provide readOnlyHint=true, so safety is known. The description adds valuable behavioral context: the tool aggregates multiple monitors in a single query, returns a per-monitor breakdown, and implies rate-limit consequences for improper use. This goes beyond annotations. It does not detail the response format, but the per-monitor breakdown is mentioned.

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 sentences with no filler. The first sentence front-loads the purpose and units. The second sentence packs the critical usage instruction (batching) and its rationale, including a concrete consequence (rate limit). Every phrase earns its place; it is efficient and well-structured.

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 tool with zero required parameters, full schema coverage, and no output schema, the description covers the essential: what it returns, how to invoke it (batch), and the omit behavior. It lacks a detailed response structure, but given the simplicity and annotations, it is reasonably complete. A small gap remains in describing the exact output format, but it is not critical for correct invocation.

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%, so the baseline is 3. The description adds significant semantics for monitor_uuids: instructing to pass every monitor in a single call, noting the cost equivalence of N monitors to one, and warning about rate limits. It also clarifies the omission behavior. For from/to, it relies on schema defaults, but the additional monitor_uuids guidance raises the score.

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 clearly states the tool returns 'Mean time to resolve (MTTR) per monitor over a date window, in seconds.' It specifies the resource (monitors), the metric (MTTR), the aggregation (per monitor), and the unit (seconds), distinguishing it from sibling tools like get_monitor_mtta and other monitor metrics. No ambiguity.

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 guidance: 'pass all monitors at once in monitor_uuids rather than calling this once per monitor' and warns about rate limiting and cost when looping. It also explains the omission behavior ('Omit to cover the whole project'). It does not explicitly contrast with alternative tools for other metrics, but the core usage pattern is clear.

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