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

readOnlyHint=true already covers the safety profile, so the bar is lower. The description adds genuine behavioral value by disclosing the shape of the result (aggregate totals plus five named breakdown dimensions), which matters because there is no output schema. It omits auth requirements, rate limits, and whether date ranges have defaults or caps.

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 tight sentences with zero filler: the primary purpose and return scope lead, the parameter note trails. Every clause earns its place.

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 read-only analytics endpoint with a simple 3-parameter schema and no output schema, the description covers purpose, prerequisite, return dimensions, and date format. Only date-range semantics (defaults, inclusivity, limits) are left unstated.

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 0%, so the description must carry the load. It clarifies that linkId references a link created via create_short_link and restates the YYYY-MM-DD format for from/to (already implied by the schema pattern). It says nothing about whether the range is inclusive, what the default window is, or any max span, leaving real gaps.

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 and resource ('Get click analytics for a short link by id') and then enumerates the return content (totals plus breakdowns by day, country, device, browser, referrer). This clearly distinguishes it from the sibling tools, which are all creation/scan/template tools rather than analytics readers.

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 parenthetical '(from create_short_link)' tells the agent the prerequisite: the link must already exist and its id comes from the creation tool. It also frames the tool as the follow-up read step. No explicit when-not-use or alternative is given, but the context is unambiguous.

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