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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds the default window (52 weeks) and the input constraint (positive integer), which is useful but thin; it says nothing about how the totals are bucketed or returned.

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?

Two short sentences, front-loaded with the scope. It repeats the weeks default twice, a small redundancy, but nothing else 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 read tool with annotations covering safety, the description is nearly adequate, but with no output schema it never hints at the return shape (one total per week? which week boundaries?). An agent can call it, but its expectations of the result are unguided.

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 only 50% — `end` is documented but `weeks` is not. The description compensates by giving the default (52) and the validity constraint (positive integer), which the schema does not carry.

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+resource ('weekly step totals') plus the window it covers, so an agent can distinguish it from get_daily_steps or get_weekly_stress without opening the schema. It doesn't explicitly name those siblings, so it falls short of the top tier.

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 use this tool versus the many nearby alternatives (get_daily_steps, get_steps_data, get_weekly_intensity_minutes). The weekly granularity is implied by the name and description but never framed as a selection criterion.

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