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

The readOnlyHint=true annotation already declares this is a safe read operation. The description adds little behavioral context beyond a purpose fragment: it does not explain what the response contains, how matching by muscle/equipment works, or how the limit affects output.

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 a single sentence fragment, so it is short but under-specified rather than well-structured. It lacks the essential context an agent needs and does not front-load the key input.

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?

With no output schema and 0% parameter description coverage, the definition should at least explain that it returns substitute exercises for exerciseId and what limit controls. The description omits both, leaving the agent with little beyond the tool name.

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 0%, so the description must carry the burden for parameter meaning. It never mentions exerciseId or limit, leaving both parameters undocumented in both structured and natural-language fields.

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 fragment 'Substitute exercises for the same muscle/equipment' gives a partial verb/resource idea but does not explicitly state that it returns alternatives for a given exerciseId. It also does not distinguish this tool from related siblings such as search_exercises, get_exercise_detail, or swap_workout_exercise.

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?

There is no when-to-use guidance, no prerequisites, and no named alternative tools. The agent must infer that this belongs in exercise-selection or substitution flows.

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