set_prescription

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

With no annotations, the description carries behavioral disclosure well: it states partial-update semantics ('Targets and the set count you leave out keep their planned values'), ownership requirement, and validation against tracked targets. It omits error behavior or return format, but covers the critical mutation semantics.

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?

Every sentence earns its place: the core action is front-loaded, followed by the critical formatting rule, the partial-update behavior, and the validation pointer. No redundant or filler text.

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 12-parameter mutation with no annotations and no output schema, the description covers ownership, partial-update semantics, target formatting, and validation. It leaves some parameter meanings (e.g., `rpe`, `percent`, `team_id`) unexplained, but the core invocation risks are addressed.

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 0% and the description compensates significantly by explaining the scalar-vs-list format for target parameters, giving a concrete example, clarifying that omitted values persist, and specifying reps are whole numbers while cues belong in `instruction`. It does not explain `rpe`, `percent`, `meters`, `team_id`, or the two required IDs, leaving some gaps.

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: setting sets and per-set targets for one exercise of a session. It distinguishes itself from sibling tools like add_exercises and update_session by focusing on prescription targets, and an agent can identify its role without opening the 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?

Provides clear context: it operates on a session you own and only accepts targets the exercise tracks, pointing to `get_workout`'s `tracks` field. It does not explicitly name alternatives or when-not-to-use, but the ownership and validation constraints give sufficient guidance.

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