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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description goes beyond that by disclosing real behavioral traits: results are free, and the app's own age gates withhold contact, tackling, heading and advanced drills until the child is old enough, which explains why a valid age query can return a reduced set. It also lists the per-drill payload, adding useful context the annotations cannot convey.

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?

It is a single tight sentence that front-loads the audience and the core constraint (age gating) before the result shape. The parenthetical could be split out for readability, but it carries genuine information about which drill categories are withheld, so nothing 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?

For a simple four-parameter read-only lookup with no output schema, the description covers audience, filtering behavior and the shape of each returned drill, which is enough for an agent to call it correctly. The remaining gap is relational — it does not explain how these drills feed into the sibling planning tools or how results are ordered.

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 every parameter is already documented, including the age range and the sport enum; the baseline for that case is 3. The description reinforces the age-gating semantics behind the 'age' filter but says nothing about 'skill' or 'at_home' that the schema does not already state.

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 a concrete verb and resource — surfacing free SSTTracker drills filtered by sport and a child's age — and previews what each result contains (steps, minutes, safety line, page link). It is clear what the tool returns, but it never references the sibling tools (get_practice_plan, get_tryout_prep, weekly_home_plan), so an agent must infer on its own why find_drills is the right entry point rather than one of those.

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 states the audience ('for parents, coaches and trainers (adults)') and implies use when looking for age-appropriate drills, which gives an agent a workable context. However, there is no explicit when-not guidance and no comparison against the practice-plan or tryout-prep siblings, so the routing decision is left implicit.

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