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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description usefully adds the API path (GET /employees/{id}/earnings) and the earnings breakdown categories, but says nothing about permission requirements, default date-range behavior, or aggregation semantics beyond the labels.

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?

A single well-formed sentence followed by the endpoint path — front-loaded and free of padding. The path is arguably redundant with the name, but it is compact and harmless.

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 and a read-only simple tool, the description largely carries the return-shape burden by enumerating the breakdown categories (lessons, other events, other compensation, total). It stops short of explaining default date range or currency/rounding behavior, leaving a minor gap.

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%, so all four parameters (employee_id, status, date_from, date_to) are already documented, including the status enum. The description only restates the existence of status and date filtering without adding format or defaulting semantics, so the baseline 3 applies.

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+resource with clear scope: total earnings of one employee, broken into lessons, other events, other compensation, and total, with optional status and date filters. This distinguishes it from teachworks_get_employee (the employee record), though it never names that 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?

Usage context is implied by 'for an optional lesson status and date range' — the agent can infer this is a filtered earnings lookup. However, there is no explicit when-to-use vs. teachworks_get_employee or teachworks_get_lesson_totals guidance, and no stated behavior when the optional filters are omitted.

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