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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the bar is lower, and the description still adds real operational context: metrics can lag up to ~10 minutes, each row carries the sample time, and the tool is read-only. It stops short of describing result shape or row limits, but for a read-only aggregation this is solid added value.

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?

Purpose and the no-free-form rule are front-loaded, and the bulleted preset list is scannable. The parenthetical explanations inside each bullet are slightly verbose but each one describes a diagnostic signal an agent would otherwise have to guess at, so the length is mostly earned.

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?

With no output schema, the description carries the burden of explaining what comes back, and it does so per preset (counts, latency per neighbor, CPU/RAM trends) plus freshness caveats. Remaining gaps are minor: no statement of row counts, pagination, or the exact fields in each result.

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, but the description adds the preset-to-scope mapping inline ('scope: container', 'scope: environment', 'scope: server'), letting the agent resolve which of server/container/environment to supply without cross-referencing per-field text. It adds little on lookback_hours or conversation_id beyond the schema, keeping it at a 4 rather than 5.

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?

Opens with a specific verb+resource ('Run a canned aggregation over Cycle's metrics store') and then enumerates all six presets with the scope and the signal each one surfaces. It explicitly differentiates itself from the sibling get_telemetry ('Historical complement to get_telemetry target=load_balancer'), so an agent can choose between them without opening either 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?

States the selection rule directly: pick a preset, then pass the input matching that preset's scope (server/environment/container). It also gives an explicit exclusion — 'No free-form queries — if none of the presets fit, say so rather than improvising' — which is exactly the kind of when-not guidance that prevents misuse.

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