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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered without the text. The description adds genuine context by listing which metric families come back and that scope is bounded by a time window, but it says nothing about sampling granularity, aggregation, or how large a window response can be.

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 sentence that front-loads the verb and resource, then enumerates the metrics and the scoping constraint. Nothing is padding and nothing needs to be moved forward.

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 two-parameter read tool with full annotations this is close to sufficient, and with no output schema the definition should at least signal the shape of the return value (time series points versus interval averages). It leaves that ambiguity open, which matters for a metrics endpoint an agent will need to interpret.

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 hours parameter already documents default 24, min 1 and max 168, so the baseline is 3. The description still contributes by framing hours as the retrieval window over historical telemetry, tying the numeric bound to a concrete meaning.

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 ('Fetches') and resource ('historical ... telemetry metrics') and enumerates the exact metric families returned (CPU %, RAM %, Disk %, Network). This separates it implicitly from status/alert readers in the sibling set, but it never names the alternative tool an agent should use for live status versus historical data.

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 'historical' and the 'specified time window' phrase hint that this is for retrospective analysis rather than current state, so an agent can infer a rough division of labor with read_server_status. That inference is never made explicit and no exclusion or alternative is named.

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