get_semesters

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

Annotations only cover safety (read-only, idempotent, open-world, non-destructive). The description adds crucial behavioral context beyond that: authentication is required, NOT_AUTHENTICATED triggers a get_captcha → login → retry flow, and login can use environment variables or prompt for credentials. This is information an agent cannot infer from structured fields.

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 compact and front-loaded: first sentence states the purpose and return shape, second gives usage guidance, third and fourth handle the auth recovery flow. No sentence is wasted.

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?

Given this is a zero-parameter, read-only, idempotent tool with no output schema, the description covers everything an agent needs: what it returns, when to call it, and the full authentication error-handling path. It is complete for its complexity.

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?

There are zero parameters, so the baseline is 4. The description appropriately doesn't invent parameter details, and the absence of filtering options is clear from the empty schema.

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 specific verb and resource: 'Get list of available semesters (id + name)'. It also explains how this tool relates to sibling data tools by noting they default to the current semester, so an agent can tell it apart.

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 explicitly says when to use it ('unless the user asks about a specific past semester') and when it can be skipped ('usually don't need to call this'). It also provides a clear recovery workflow for NOT_AUTHENTICATED and missing credentials.

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