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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds real value beyond that by explaining the permission semantics (student self-view vs. teacher/TA all-view) and by previewing the returned canviewallgrades flag with a typical value, which sets callers' expectations.

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?

Front-loaded with the core purpose and only three sentences. The parenthetical 'e.g. whether it can see its own grades vs. ... everyone's grades' restates the same idea as the opening clause, a small redundancy that keeps it from a 5.

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 structure needn't be described, and the description still explains the meaning of the key returned flag and its typical value. Annotations cover safety. Little is missing for a single-parameter 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?

Only one parameter, and the schema already documents course_id at 100% coverage including a pointer to list_courses. The description adds nothing further about the parameter, 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?

A specific verb and resource: 'check what grade-related permissions this account has in a course'. It also scopes the answer ('own grades vs. everyone's grades'), which implicitly separates it from get_grades/get_grades_overview. It does not name those siblings outright, so it stops 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?

Usage is implied rather than stated: an agent can infer this is a pre-flight capability check before fetching grades, but the description never says when to prefer it over get_grades or get_grades_overview. The 'Most student accounts will see canviewallgrades=False' line is expectation-setting, not guidance on alternatives.

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