get_marks

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld), so the bar is lower. The description adds genuinely new behavior: it requires login and tells the agent to follow the error's `recovery` array on NOT_AUTHENTICATED. It stops short of explaining pagination or the shape of the recovery flow, keeping it at a strong 4.

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-loads the purpose, then the alternative, then optional-param and error-handling notes. Every sentence carries information, though the dense field enumeration is slightly heavy. No filler or repetition.

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?

No output schema exists, yet the description thoroughly describes the return fields, the auth requirement, and the error-recovery path. For a two-param read tool whose annotations already carry the safety profile, nothing an agent needs to invoke it correctly is missing.

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%, so both parameters are already fully documented, including the cache-bypass semantics of `refresh` and the format of `semesterId`. The description's 'semesterId is optional; omit for current semester' merely restates the schema, adding no new syntax or constraints. Baseline 3 is appropriate.

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?

States a specific verb and resource ('Get internal marks/assessment scores') and enumerates the exact fields returned per component (raw marks, max marks, weightage, class average, status). It explicitly distinguishes itself from the sibling get_internal_totals, so an agent can route correctly without opening either schema.

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?

Names the alternative (get_internal_totals) and the exact condition that selects it ('when you want the TOTAL for each subject rather than the component breakdown'). It also gives guidance on the optional semesterId and what to do on a NOT_AUTHENTICATED response.

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