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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds nothing behavioral beyond the annotations: it does not say whether the streak is computed live, whether it counts current versus longest streak, or how a student with no sessions is handled.

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?

One short sentence with no padding, and the core subject (streak length) is front-loaded. It is slightly under-structured for a tool description, being a fragment rather than a complete statement of action.

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?

This is a simple single-parameter read with good annotations, so the bar is modest, but with no output schema the description should clarify the return shape, e.g. whether days and weeks are both returned and what the weekly target field represents. As written, the agent knows roughly what it gets but not its structure.

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 coverage is 100% and the single parameter is documented as 'The student_id from list_students', which is a useful cross-reference. The description only mentions 'the student' generically and adds nothing beyond the schema, so the baseline of 3 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?

The description names the specific resource: a training streak measured in consecutive days or weeks, plus the weekly target. That is concrete enough for an agent to know what comes back. It is a noun phrase rather than a verb+resource statement and does not distinguish the tool from related reads like get_student_summary or get_workout_leaderboard.

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?

There is no guidance on when to call this versus alternatives such as get_student_summary or get_students_activity, and no mention of prerequisites or companions like set_weekly_target. Usage is only inferable from the resource name.

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