Final grades

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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered. The description goes beyond them by disclosing data-availability semantics ('a column the school does not show is unavailable; an empty or - raw value is not given yet'), which tells the agent how to interpret nulls/dashes rather than misreading them as zeros. Lacks any note on freshness or caching.

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?

Three tight sentences: what it returns, how to read gaps, and where to go instead. Front-loaded with the resource and zero filler.

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?

Output schema exists so return values needn't be described, and the null/unavailable-column caveat fills the main interpretive gap. Slightly short of 5 because openWorldHint implications (external school system, possible staleness) go unaddressed.

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?

Single required parameter with 100% schema description coverage ('Login alias from list_accounts'), so the schema already carries the semantics. The description adds nothing about the parameter, but with one fully-documented param the baseline of 4 applies.

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?

Names the exact resource (midterm, predicted and annual grades per subject) and its provenance ('as the school published them'), which distinguishes it from the raw per-grade siblings. An agent can tell this is the aggregated/summary view.

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 routes the agent: 'For individual grades use get_grades or get_grades_window.' That is a clear when-not with named alternatives.

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