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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world). The description adds genuinely useful behavioral context beyond that: it surfaces user-marked Rest/Sick/Travel Days even when no workout exists, and states the return is an interactive chart plus summary.

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 short, front-loaded sentences with zero filler; the scoping detail (time windows) leads, followed by the notable behavioral nuance and the return shape.

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 single-parameter read tool with an output schema and full annotation coverage, the description supplies the important remaining context (rest/sick/travel day inclusion, chart output). The only meaningful gap is the absence of routing guidance versus sibling visualization tools.

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 schema already documents the enum values, default (7d), and meaning of 'range'. The description only repeats the same window values, adding no syntax or semantic detail beyond the schema.

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: produces a visual training trend, with the supported time windows enumerated. It's clearly a chart/aggregate tool rather than a raw-data tool, distinguishing it implicitly from list_workouts and show_workout, but it never names a sibling to make the boundary explicit.

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?

Usage is implied by 'visual training trend' and the range parameter, but the description offers no when-to-use guidance or exclusions relative to the many sibling show_*/list_* tools. An agent must infer that this is for a charted overview rather than per-workout detail.

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