Icu Get Gap Histogram

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

Annotations already establish this as a read-only, idempotent, non-destructive open-world query, so the safety profile is covered. The description adds real semantic context beyond that: it explains that the output is a time-in-zone distribution and that values are elevation-normalized. It does not discuss cost, pagination, or data availability for activities without elevation data, which keeps it out of the top band.

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, with the core definition and the elevation-normalization qualifier front-loaded before the sibling redirect. Every clause carries information; nothing is padding.

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 annotations cover the safety profile. With a single fully documented parameter and a clear statement of what the histogram represents, nothing an agent needs to call this correctly is missing.

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?

There is only one parameter (activity_id) and schema description coverage is 100%, so the schema fully carries the load. The phrase 'within a single activity' reinforces the scoping but adds no syntax or constraint detail beyond the schema, which matches the baseline for fully documented parameters.

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 operation (time-in-zone distribution of grade-adjusted pace), a specific scope (a single activity), and the key qualifier (elevation-normalized). It also names the sibling it is not, so an agent can distinguish it from icu_get_pace_histogram without opening either schema.

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?

Gives an explicit use case (trail running where raw pace is misleading) and an explicit routing rule to the alternative (raw pace -> icu_get_pace_histogram). Both when-to-use and when-to-use-something-else are stated outright.

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