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

No annotations are present, so the description bears full responsibility for behavioral disclosure. It only notes a vague return format '{error}' and does not clarify assumptions (e.g., equal weighting), error handling, or side effects. This is insufficient for a calculation tool.

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 consists of two concise sentences. The first clearly conveys the core purpose, and the second provides a useful cross-reference. No extraneous content is present.

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 the tool has an output schema (implied by 'Returns'), the description need not detail return values. However, it does not mention preconditions (e.g., exam weight assumptions) or edge cases. For a straightforward calculator, this is minimally adequate but leaves gaps.

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?

All four parameters are documented in the input schema with descriptions (100% coverage). The description adds no additional semantic meaning beyond what the schema already provides, meeting the baseline expectation.

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 clearly states the tool calculates the required grade on remaining exams to achieve a target average. It identifies the specific calculation and resource (grade needed), and distinguishes from siblings by referencing 'education' calculators. However, the mention of 'Returns: {error}' is somewhat ambiguous.

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 pointer to related calculators via 'See list_bundles for related education calculators', giving implicit context. However, it lacks explicit guidance on when to use this versus alternatives, and no when-not or exclusion criteria are provided.

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