get_publication_stats

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

With no annotations provided, the description carries the full burden. It clearly states this is a read-only operation ('Read') and lists the exact metrics covered. It also notes it takes no arguments. It doesn't discuss possible rate limits or time windows for 'recent,' but for a stat-read tool this is reasonably transparent. A 5 would require more detail on data freshness or pagination, but the core behavior is clear.

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 description is exceptionally concise: two sentences, front-loaded with the action/scope, and every word adds value. It lists the key metrics and then directs users to the alternative without any fluff.

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 zero-parameter read-only stats tool, the description is complete. It tells exactly what data is returned, that no arguments are needed, and where to go for deeper metrics. No output schema exists, but for this simple tool, the description sufficiently covers what the agent needs to know.

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 has zero parameters, so the schema coverage is vacuously 100%. The baseline for 0 params is 4; the description reinforces this by explicitly stating 'Takes no arguments,' which is helpful but adds little beyond the schema. No deduction needed.

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 uses a specific verb ('Read') and clearly identifies the resource ('your Substack publication') and the exact metrics returned (subscribers, ARR, site views, open rate). It also explicitly contrasts with the deeper get_analytics tool, distinguishing it from the most likely sibling.

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 description gives clear when-to-use guidance for headline stats and explicitly states when not to use it: 'For anything deeper — retention, churn, growth sources, referrals — use get_analytics.' This provides an explicit alternative, satisfying the highest bar for usage guidance.

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