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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds genuinely useful non-schema context: it requires the user's Cotlet API key with access to this app, and it discloses the allowed period granularities. Return content is also characterized as dashboard-equivalent figures.

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 metric list is front-loaded and the auth requirement is stated plainly. There is mild redundancy between the opening sentence and the second sentence, which re-enumerates the same subscriber and revenue figures, but the text stays short and readable.

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, the description carries the burden of explaining returns and does so by naming the metric categories. Auth prerequisites and period options are also covered, leaving only minor gaps such as whether results are workspace-scoped or paginated.

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 single enum parameter already documents '7d, 30d or 90d. Default: 30d.' The description restates the same period options without adding syntax or edge-case meaning, so the baseline 3 is appropriate.

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 (get) and resource (publication stats), then enumerates exactly which metrics are returned (total, paid, new, churned subscribers and revenue). It is clearly distinguishable from a post-level stats tool, though it never names a 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?

The description gives implied context by saying these are 'the same figures as the publisher dashboard,' which tells the agent this is a high-level reporting call, but it offers no explicit when-to-use, when-not-to-use, or alternative tool guidance.

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