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

Annotations already cover the safety profile (readOnlyHint=true, openWorldHint=true), so the bar is lower. The description usefully adds the default aggregation behavior and the constrained enum values, but says nothing about what the returned series represents, its units, or behavior on empty/partial ranges.

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 resource and scope, and no filler. Minor redundancy: the default is stated twice ("aggregated weekly (the default)" then "Defaults aggregation=\"weekly\"").

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?

With no output schema, the description carries the burden of explaining the result, yet it never defines what a running tolerance value is or its units. For a read-only metric tool with covered annotations and mostly documented params it is adequate, but the core output concept is left undefined.

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 67%, and the only undescribed parameter (aggregation) is precisely the one the description documents: its default of "weekly" and its restriction to {daily, weekly}. That is real added meaning beyond the schema enum, and it also clarifies the parameter is narrower than analogous methods.

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 metric (running tolerance) and the retrieval scope (date range, aggregated weekly or daily). It also gestures at sibling differentiation by noting the aggregation set is narrower than the FTP/lactate methods, though it does not name those siblings directly.

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 statement of when to choose this tool over get_lactate_threshold or get_functional_threshold_power_range, nor any prerequisite or exclusion. The FTP/lactate reference only explains the enum restriction, not tool selection, so the agent must infer usage context entirely.

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