get_grade_history

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

Annotations already declare readOnly/idempotent/non-destructive, yet the description adds genuinely new behavioral context: the auth prerequisite, the exact NOT_AUTHENTICATED sentinel in the response, the env vars login consumes, and the user-prompt fallback when credentials are missing. That is precisely the kind of auth and error-contract detail the annotations cannot convey.

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 purpose and returned payload are front-loaded in the first sentence, followed by the recovery procedure in priority order. The credential sentence is slightly dense but each sentence carries actionable instruction with no filler.

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 parameters, no output schema and a covered annotation set, the description compensates by describing the returned content itself and the full auth/retry loop. An agent has everything it needs to call this tool and recover from the expected failure.

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?

The tool takes zero parameters, so the baseline is 4 and there is no parameter semantics for the description to elaborate. It correctly avoids inventing arguments.

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 and resource and then enumerates the returned scope (CGPA, total earned credits, per-semester GPA + courses + grades grouped by exam month), which implicitly separates it from siblings like get_semester_grades or get_marks. It stops short of naming an alternative explicitly, so it does not quite reach the top band.

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?

It provides strong conditional guidance for the failure path (NOT_AUTHENTICATED -> get_captcha -> login -> retry) and the credential fallback, and states the login prerequisite outright. It never says when to prefer this tool over get_semester_grades or get_marks, so selection guidance is inferred rather than stated.

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