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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint=false, so the safe-read profile is fully covered without the description's help. The description adds only the filterable dimensions, which is parameter framing rather than behavioral disclosure (no mention of result volume, ranking, or how results are ordered).

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?

Two short sentences, front-loaded with purpose then examples, with no wasted prose. The opening largely echoes the title, which is a minor redundancy rather than bloat.

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 readonly filtered-list tool with zero required params, 100% schema coverage and safety fully covered by annotations, and no output schema to explain, the description supplies enough to call it correctly. It omits any note that all arguments are optional and that omitting muscle/equipment returns an unfiltered list, a small remaining gap.

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 100% and the muscle/equipment enumerations plus the level and limit semantics are documented in the schema itself. The description restates muscle and equipment but says nothing about level or limit, so it adds no meaning beyond the schema. Baseline 3 applies.

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 first sentence names a specific resource (exercises) and its two filters (muscle, equipment), so an agent knows exactly what this returns. It is distinguishable from get_exercise (single detail) and get_workout_plan (programs) by implication, though it never names those siblings explicitly.

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 example queries ("what can I do for chest with no equipment?", "glute exercises with bands") give concrete trigger conditions, and "Give a muscle, equipment or both" clarifies that filters are optional and combinable. No explicit when-not-to-use or alternative-tool routing, which keeps it short of a 5.

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