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

Annotations already declare the tool as read-only, idempotent, and non-destructive. The description adds meaningful context beyond annotations by explaining that free accounts receive a basic total and an upgrade hint, while Pro accounts receive full breakdowns. This clarifies the behavioral difference based on account status, providing useful context for the agent.

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 sentence that efficiently communicates the core purpose and the key account-tier distinction. No unnecessary words or repetition, making it highly concise and well-structured.

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?

The tool is simple with only 3 parameters, all described, and an output schema exists. The description adds the crucial account-tier nuance. However, it does not clarify what 'basic total' or 'full breakdowns' specifically include, though the output schema likely covers this. Given the low complexity and rich structured data, the description is nearly complete.

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%, with all three parameters (alias, domain, period) fully described. The description adds no additional parameter-level meaning, so a baseline score of 3 is appropriate. The description's mention of 'basic total' vs 'full breakdowns' indirectly relates to period parameters but does not enhance parameter semantics beyond the schema.

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 and resource: 'Get link analytics.' This clearly distinguishes the tool from siblings like get_link and list_links, as 'analytics' implies statistical data. However, it does not explicitly contrast it with alternatives, so a small deduction for lack of explicit sibling differentiation.

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?

No guidance is provided about when to use this tool versus alternatives. The description only mentions account-tier differences (free vs. Pro) but does not state when to choose get_link_stats over get_link or list_links. This leaves the agent to infer usage solely from the tool name.

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