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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds genuinely new context by stating 'Unauthenticated', which tells the agent no credential handling or auth-failure path is required — a real behavioral fact not in the annotations. It stops short of noting latency/RTT effects on skew measurement, which would have been the one remaining useful caveat.

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 core sentences are tight and front-loaded, but the trailing 'Examples: Current server epoch ms' is a truncated fragment that conveys nothing beyond the first sentence and reads as leftover template text. That dead sentence costs it a point against an otherwise two-sentence description.

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 zero parameters, an output schema, and full annotation coverage, the description carries the remaining burden: what the value means (ms epoch), why to call it (skew), and that it is unauthenticated. Only a note about round-trip latency affecting skew estimation is missing, which is a refinement rather than a blocker.

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 tool takes zero parameters, so the schema baseline of 4 applies. The description correctly says nothing about inputs and instead spends its words on the return unit, which is the only semantic worth clarifying here.

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 and resource ('Return the protocol server wall-clock time') plus the exact unit ('Unix epoch milliseconds'), which is the detail that matters for this resource. No sibling tool in the list returns time, so it is trivially distinguishable from the get_market/get_positions family.

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?

Gives a concrete usage context: 'Use before quoting to measure client clock skew,' which tells the agent exactly when this belongs in a workflow. No exclusions or alternatives are needed since no sibling offers overlapping capability, so the absence of 'use X instead' guidance is not a real gap.

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