postfix_log_stats

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

Annotations already declare readOnlyHint=true, openWorldHint=false, and idempotentHint=false, so the safety profile is covered. The description adds what is aggregated and that deferral entries carry a category and hint, but says nothing about cost on large windows, pagination, or how the non-idempotent aggregate behaves between calls.

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?

A single sentence, front-loaded with verb and resource, with no filler or restatement of the name. The long enumerated clause is information-dense rather than padded, though it could be split for scanability.

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?

An output schema exists, so return-value explanation is not required, yet the description still orients the agent on what categories come back. Nothing essential is missing for a read-only aggregation tool, though behavior on very large windows (cost, truncation) is unaddressed.

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 description coverage is 100%, so 'top', 'since', and 'domain' (including the leading-dot subdomain rule) are already fully documented in the schema. The description adds no parameter-level meaning beyond that, which is the expected baseline when the schema does the work.

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 (Aggregate) and resource (Postfix mail log) with the scope (time window) and enumerates the exact output dimensions: totals, per-domain outcomes, failing domains, deferral/bounce groupings, DKIM selectors. An agent can distinguish this from siblings like postfix_log_trace, postfix_log_trend, and postfix_queue_summary without opening a 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?

The enumerated output categories imply the tool is for a summarized overview of recent log activity, but there is no explicit when-to-use guidance and no mention of which sibling to pick instead (e.g. log_trace for a single message, log_trend for time-series). Usage is inferable but not stated.

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