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

Annotations already declare readOnly/idempotent/closed-world, so the safety profile is covered. The description adds real behavioral context (max 8 courses, credit-hour weighting, 4.0 scale, cumulative requires prior GPA), but says nothing about omitted-grade handling, default-filled courses, or output shape.

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 compact sentences, with the computational semantics front-loaded and the reference URL trailing. Nothing is bloated, though the URL contributes little to invocation decisions.

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 an 18-parameter tool with no output schema, the description covers inputs and results at a high level but omits how many courses must be supplied, how blank grades are treated, and what the response contains. Adequate, not 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%, so the baseline is 3. The description adds meaning to the credit parameters (weighting) and implies gpa0/credits0 feed the cumulative result, but adds no formatting or edge-case guidance 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?

States a specific verb+resource and rich scope: letter grades A–F with plus/minus, credit-hour weighting, up to 8 courses, 4.0-scale term GPA plus new cumulative GPA. It does not distinguish itself from the sibling grade_calculator, which is the main gap keeping it from 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?

No explicit when-to-use, when-not-to-use, or alternative tool is named, despite a closely related sibling (grade_calculator). The agent must infer applicability from the computation described.

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