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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the safety profile is covered. The description adds that the result includes canonical page URLs and ids, but doesn't mention ordering, pagination, or any other behavior. Given the annotations, the description adds modest context beyond them.

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 sentences with no fluff. The core purpose is front-loaded, followed by a clear usage directive. Every word earns its place.

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 read-only list tool with one optional parameter, the description covers what it returns and how to use it. Annotations handle safety, no output schema exists, and nothing essential is missing for an agent 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?

Schema description coverage is 100% (subject_id has a description), so the schema fully documents the parameter. The description doesn't add any extra meaning about the parameter—it only mentions return content, not parameter semantics. Baseline 3 is appropriate when the schema covers the parameter.

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?

Description clearly states the tool returns the full catalogue of school subjects with grades, URLs, and ids. It specifies the resource (subjects) and the action (list/return), and distinguishes itself from siblings by framing it as the discovery step for ids needed by search_lessons and get_course_outline.

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?

Explicitly instructs the agent to use it first to discover subject/course ids needed by other tools. This provides clear when-to-use guidance and implies the workflow sequence, though it doesn't state when not to use it, the direction is unambiguous.

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