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

Annotations only cover the safety profile (readOnly, idempotent, openWorld), so the description carries the real behavioral burden — and it does, disclosing that the data is index-lagged and that a `freshness` object with lagSeconds and stale exists. It stops short of stating magnitude, refresh cadence, or rate limits, but the staleness caveat is exactly the context an agent needs.

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?

Two sentences, zero filler. The returned fields are front-loaded, followed immediately by the operational caveat about freshness — the most decision-relevant information is placed where an agent will read it first.

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 and no annotations covering data quality, the description supplies the returned field list and explains the freshness sub-fields, which is enough to call and interpret the tool. It could be tighter about what 'activity in 24 h' actually contains, but nothing essential is missing for a no-arg status read.

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 and the schema is fully closed, so there is no parameter semantics to explain; the description correctly spends no words on inputs. Baseline for a 0-param tool.

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 (the Midnight network) and enumerates the exact facts returned: protocol version, epoch, block time, and 24h activity. The 'as we index it' qualifier and the 'network' scope implicitly separate it from the sibling get_midnight_contract, though it never names that sibling explicitly.

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?

It gives one concrete usage rule — 'check freshness before quoting any Midnight figure as current' — which is genuinely actionable. However, it offers no guidance on when to call this tool versus related siblings like get_block, get_epochs, or get_midnight_contract, so the when-to-use framing is only partial.

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