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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint, so the safety/behavior profile is covered. The description adds essentially no behavioral context beyond that (no note on result count behavior, exhaustiveness, or that any flaky matching is fuzzy). It neither contradicts nor enriches the annotations materially.

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 opening 'Plan My Workout. Exercises for a muscle and the equipment the user has' largely restates the tool name and title, wasting the front-loaded position on redundant text before reaching the genuinely useful example utterances. The examples and closing instruction do earn their place.

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 read-only, zero-required-param list tool with full schema coverage and no output schema, the description supplies enough to call it correctly, including example phrasings and the muscle/equipment expectation. Richer detail on sibling differentiation and result breadth would make it complete.

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 100% with enums and ranges documented inline, so the schema does the heavy lifting. The description's 'Give a muscle, equipment or both' adds the intent that at least one filter is expected even though all four parameters are technically optional, which is a small but real clarification over the schema.

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 states the resource clearly (exercises filtered by muscle and/or equipment) and supports it with concrete example phrasings. It does not, however, distinguish itself from sibling planmyworkout_get_exercise or planmyworkout_get_workout_plan, so an agent must infer which one returns a list versus a single item or a full plan.

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 four example requests ('what can I do for chest with no equipment?', 'glute exercises with bands', etc.) give clear, concrete context for when to select this tool. It stops short of explicit exclusions or naming the alternative siblings to use instead, so it is clear-context guidance rather than full when/when-not routing.

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