Get course grades

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

With no annotations, the description carries the full burden of behavioral disclosure. It specifies the output format (each item fields), explains the meaning of a '-' grade, and clarifies that credentials are taken from MCP settings headers rather than the agent. This gives the agent necessary operational details without stating explicit read-only status, though 'get' implies it.

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 description is concise and efficiently structured: the first sentence states the purpose, the second explains the output format, and the third addresses credentials. Every sentence earns its place with no fluff, and the main purpose is front-loaded.

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 a simple tool with one parameter and no output schema, the description is complete: it provides the return structure, the meaning of a special grade value, and the credential source. It doesn't mention error cases or pagination, but these are minor for this scope. The agent has everything needed to call it correctly.

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 schema already describes course_id fully with 100% coverage, including the note 'from list_courses.' The description repeats this same information without adding new semantic meaning about the parameter. Since the schema covers it, the baseline is 3; the description adds no additional parameter-specific insight.

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 states a clear verb and resource: 'Get the student's own grade items for one course.' It distinguishes itself from siblings by focusing on grades specifically, and it clarifies the input is a Moodle course id from list_courses. This unambiguously differentiates it from course listing, announcements, and assignment tools.

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 description provides a clear prerequisite: the course id must come from list_courses. It implies the tool is for retrieving grades for a single course, but does not explicitly state when not to use it or name alternatives. The context is clear enough for an agent to know this is the go-to for grades, but it lacks explicit exclusions.

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