swap_exerciseReplace an exercise with a valid same-area alternative. scope 'today' = just this session; scope 'program' = going forward. The new lift starts fresh (day-one calibration).
| Name | Required | Description | Default |
|---|---|---|---|
| scope | No | Default 'program'. | |
| dayIndex | No | ||
| exerciseId | Yes | ||
| toExerciseId | Yes |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden of behavioral disclosure. It explicitly reveals that the new lift starts fresh with day-one calibration, which is a non-obvious side effect. It also clarifies the meaning of scope. It does not mention reversibility or impact on existing history, but the key behavioral trait is disclosed.
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 description is two sentences, front-loaded with the main action and followed by essential scope semantics. Every sentence earns its place with zero fluff.
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?
The description covers the main purpose and scope behavior, and the calibration reset is an important detail. However, since there is no output schema, the description does not need to explain return values, but the 'dayIndex' parameter remains unaddressed, which is a gap for a tool with program-level mutations.
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 description coverage is only 25% (only 'scope' has a schema description). The description adds meaning for 'scope' by explaining today vs. program, and implies 'toExerciseId' must be a valid same-area alternative. However, the 'dayIndex' parameter is completely unexplained, and the IDs are not elaborated beyond their obvious nature.
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 clearly states 'Replace an exercise with a valid same-area alternative', which is a specific verb+resource. It distinguishes itself from sibling tool 'list_swap_options' by focusing on the action of replacement rather than listing options.
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 description explains the two scope values ('today' = just this session; 'program' = going forward), providing clear context for when each should be used. However, it does not explicitly mention alternatives or exclusions, such as 'use list_swap_options first to see valid alternatives'.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Each tool targets a distinct action or resource: program retrieval, session guidance, workout logging, readiness check-in, exercise swaps, nutrition targets, and meal planning. Even the closely related list_swap_options and swap_exercise have clear separation (viewing alternatives vs. applying a change). No two tools could be reasonably confused.
Tool names are predominantly snake_case with a verb_noun pattern (get_program, list_swap_options, log_workout, regenerate_program, swap_exercise). However, a few are plain nouns (changelog, meal_plan, nutrition_targets) and readiness_checkin is a noun phrase, breaking the strict verb-first convention. This is a minor deviation that does not hinder readability.
With 10 tools, the server is well-scoped for a fitness coaching domain. Every tool addresses an essential aspect of the coaching loop: program viewing, daily session delivery, workout logging, readiness tracking, nutrition guidance, exercise modification, and explanation of changes. The count is within the ideal range and none feel redundant.
The tool surface covers the core lifecycle: get program, regenerate program, view today's session, log workout, check in readiness, swap exercises, and access nutrition targets and meal plans. Notable gaps include no explicit workout history/retrospective tool and no direct profile management, but these are likely handled externally or can be worked around. The inclusion of a changelog nicely closes the feedback loop.