get_semester_grades

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

Annotations already declare readOnly/idempotent/non-destructive and open-world, and the description adds substantial context beyond them: the NOT_AUTHENTICATED response contract, the get_captcha → login → retry sequence, and the env-var credential fallback with user-prompt escalation. This is rich, actionable behavioral disclosure.

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 core purpose is front-loaded in the first sentence, and the remaining sentences cover auth behavior that genuinely aids correct invocation. It is somewhat verbose with the auth flow spelled out inline, but each sentence carries information.

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, the description compensates by naming the return contents (course-wise grades + GPA) and the special NOT_AUTHENTICATED signal, and it fully covers the auth prerequisites and recovery. Nothing an agent needs to call this correctly is missing.

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 coverage is 100% and the schema itself already documents semesterId including the 'omit for current semester' behavior. The description restates this ('semesterId is optional; omit for current semester') but adds no format syntax beyond the schema's example, so 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 scope: 'Get grades for a specific semester (course-wise grades + GPA)'. An agent can tell this returns per-course grades plus GPA for one semester. However it does not distinguish itself from the very close siblings get_grade_history and calculate_gpa, leaving overlap to inference.

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?

Provides clear operational context ('semesterId is optional; omit for current semester', 'Requires login') and a full retry flow. But it never says when to prefer this over get_grade_history or calculate_gpa, so routing among siblings is left implicit.

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