current_grades

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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds genuinely useful return behavior: hidden gradebooks are still listed with access="hidden" rather than dropped, which an agent could not infer from the annotations.

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 no filler, and the primary behavior (return all visible course totals) is front-loaded before the hidden-gradebook caveat.

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?

An output schema exists, so return values needn't be explained, and annotations cover safety. The hidden-gradebook disclosure rounds it out, though the unexplained include_past parameter is a residual gap for an otherwise simple read tool.

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?

There is a single parameter, include_past, with 0% schema description coverage, so the description must carry it. The description says nothing about the include_past flag or how past courses are handled, leaving the only parameter undocumented.

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 gives a specific verb+resource (current course total) and a clear scope (every course the student can see). It implicitly distinguishes itself from single-course siblings like course_grade, but never names them explicitly, so it falls short of a 5.

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 scope (all visible courses) implies the use case for a bulk listing versus a per-course lookup, but there is no explicit when-to-use, when-not-to-use, or named alternative among siblings such as course_grade or grade_history. Usage is only implied.

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