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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds genuine value by enumerating the returned metrics (clicks, unique clicks, conversions, conversion rate, period/all-time earnings), which matters because no output schema exists, and by flagging the partner-view perspective. It does not disclose pagination or what happens when the partnership is not found.

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 sentences, front-loaded with the purpose followed by the return contents, and nothing is padded. The parenthetical '(partner view)' is slightly cryptic without explanation of the contrasting view, which keeps it from a 5.

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 two-parameter, read-only stats tool with full schema coverage and no output schema, the description covers purpose, scope, and return fields adequately. The remaining gap is procedural: it never explains how to source partnership_id or what the period_days default means in the response, though the schema supplies the default value itself.

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 both parameters documented, including the 1-365 range and default of 30 for period_days, so the schema carries the burden. The description's reference to 'period/all-time earnings' faintly echoes the period concept but adds no format, timezone, or edge-case guidance beyond the schema — 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?

The description opens with a specific verb and resource ('Get click and conversion statistics for a specific partnership') and scopes it with '(partner view)', which distinguishes it from program-side stats tools like get_affiliate_stats. It stops short of naming the sibling tools an agent would confuse it with, so differentiation is implied rather than explicit.

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 phrase 'for a specific partnership you belong to' implies the applicable context but gives no explicit when-to-use or when-not-to-use rule against get_affiliate_stats, get_aggregate_stats, or get_agentlink_stats. It also omits the prerequisite that an agent must first obtain a partnership_id via list_affiliate_partnerships.

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