swap_plan_exercise

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

Annotations declare it's a non-readonly, open-world, non-idempotent, non-destructive mutation. The description adds critical context beyond that: it returns a preview and saves nothing unless apply=true, and only after user approval. This two-phase safety behavior is exactly the kind of context annotations can't convey.

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 core behavior is front-loaded in the first sentence, followed by a compact example and a single-sentence save-semantics note. Zero wasted 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 7-param mutation tool with no output schema, the preview/apply contract is well covered. The main gap is the unexplained 'plan' parameter, but the critical behavioral and safety information an agent needs is present.

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?

With 0% schema coverage, the description carries the burden. It explains apply (preview vs save) and sets/reps (override behavior) well, but leaves day, plan, exercise, and new_exercise to inference from their names, and the 'plan' parameter is entirely unaddressed.

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 ('Replace') and resource ('one exercise on a day of the training plan with another') with the target-preservation behavior included. It is clearly distinguishable from siblings like add_plan_exercise and remove_plan_exercise, and the example makes the operation concrete.

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?

Explains the when: sets/reps override targets otherwise preserved, and lays out the preview-then-apply workflow with the condition that apply=true only follows user approval. It doesn't explicitly rule out add/remove siblings but the replacement semantics make the boundary clear.

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