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

Goes well beyond the annotations: discloses that the workout is published to a public Explore page (no personal details), that `link` opens it in GetFit's Player with timers, and that the agent should read out safety_notes. These are meaningful side-effect and output-handling details an agent needs and annotations alone (readOnlyHint=false, openWorldHint=true) don'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?

Front-loaded with the core question and purpose, then output guidance, then inputs and an example. Slightly dense sentence about the Explore page and Player, but every sentence carries information. No filler.

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, the description fully compensates by describing the return contents (warm-up, exercises with sets/reps/rest/effort, safety_notes, link) and the public-posting behavior. An agent has everything needed to call it and present results correctly.

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 71% and the description reinforces that all inputs are optional and lists them, plus supplies a concrete example call ({"focus":"legs","minutes":30,"equipment":"from home","avoid":["knees"]}) that clarifies accepted value shapes. That example adds real value beyond the schema, though it doesn't deepen semantics of enums like intensity.

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?

Specific verb+resource: builds a complete session matching time, gear, and avoidances. The framing question plus 'builds a complete session' makes clear it's a generative tool, distinguishable from retrieval siblings like get_workout and search_workouts. It doesn't explicitly name those siblings, which keeps it just below 5.

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?

Clear context for when to invoke: when a person wants a workout fitted to minutes, equipment, and constraints. The example anchors typical use. However, it doesn't state when NOT to use it or explicitly route to search_workouts/get_workout as alternatives, so it falls short of 5.

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