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

Annotations already establish read-only, idempotent, non-destructive behavior. The description adds meaningful context beyond annotations by naming the metrics returned (totals, daily hits, top countries and referers) and the supported lookback windows with a default.

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 a single compact sentence that front-loads the read-only nature, the core purpose, the time windows, and the returned data. There is no filler.

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 simple read-only statistics tool with no output schema, the description adequately explains what data comes back and how to choose the time window. The main omission is explicit identification requirements for the redirect ID/UUID parameters.

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?

With 0% schema description coverage, the description does valuable work: it documents the 7/30/90-day options and default, and explains that the redirect is identified by ID or UUID. However, it does not state that one of the two identifiers is required or whether they are mutually exclusive, leaving a meaningful semantic gap.

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 states a specific verb ('Hit statistics') and resource ('one redirect') plus the time windows and returned metrics. It clearly distinguishes this stats tool from sibling tools like get_redirect (details) and list_redirects (enumeration).

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 makes clear the tool is for retrieving hit statistics for a specific redirect over 7, 30, or 90 days. It does not explicitly name alternatives such as get_redirect or say when not to use it, so it falls short of full when/when-not routing guidance.

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