time_in_resistance

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

With no annotations the description carries the full burden, and it does add real behavioral context: results are a pure aggregation of stored blocks and are only as valid as the logged blocks. It stops short of saying what happens when no blocks are logged (empty result vs error) and gives no indication of scope across rides or any cost/size characteristics.

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?

The measure statement is short and front-loaded, but the leading '§18.2' is an opaque cross-reference that means nothing without the external document, and 'The same shape as time-in-zones' points at a tool that is not in the sibling set. Both sentences spend space on references the agent cannot resolve.

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?

An output schema exists, so return values need not be explained, and the unit/granularity (0.5-turn bands, LOCAL week) is covered. The remaining gap is scope: with zero parameters the agent cannot tell whether this aggregates every stored ride block or only a default window, and the prerequisite relationship to save_ride_blocks/ride_blocks is only hinted at.

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?

The tool takes zero parameters, so per the baseline this is a 4; there is nothing for the description to disambiguate. The schema is fully self-describing (empty object).

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 measure precisely: minutes bucketed per resistance value and per 0.5-turn band, per LOCAL week, produced by "pure aggregation of stored blocks." That is a specific verb+resource+granularity. It does not, however, distinguish itself from actual siblings in the list (resistance_history, ride_blocks) — it instead compares to 'time-in-zones', which is not among the sibling tools, so the differentiation target is unverifiable.

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?

The clause 'the only ride read that rests on NO assumption beyond the blocks having been logged correctly' implies when to prefer it (when an assumption-free ride read is wanted, versus derived metrics like efficiency_factor or drift_onset), but that comparison is never made explicit. There is no stated when-not condition and no named alternative tool.

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