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

Annotations only declare readOnlyHint=true; the description goes well beyond that by explaining that these are hard constraints enforced server-side (plans violating dietType/foodAllergies/mealsPerDay are rejected; plans requiring unowned equipment are unusable) and that the tool returns null when unset. That is exactly the context an agent needs to interpret the result.

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?

Three sentences, each load-bearing: the field inventory, the hard-constraint consequence, and the timing/null-return directive. No filler, and the consequences and call-timing are front-loaded rather than buried.

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?

There is no output schema, so the description carries the return-value burden and does so ('Returns null if they have not set any') while also listing what a non-null result contains. Nothing an agent needs to call this correctly is missing.

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 lone clientId parameter is undocumented in both places. However, clientId on a get_client_preferences tool is self-evident in meaning, and the description does not need to invent syntax for it. Baseline 3 for a trivially-named single parameter with no added semantics.

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 names a specific resource (the client's own stated constraints) and enumerates its contents — diet type, allergies, cuisines, meals per day, training days, equipment, session length, notes. This is clearly distinguishable from neighboring getters like get_client_profile or get_client_onboarding, so an agent can select it without opening the schema.

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?

It gives an explicit when and a why: 'Call this BEFORE create_workout_plan/create_diet_plan on every run, including weekly adjustments.' It even pre-empts the common mistake of reusing stale data ('clients change these between runs'). This is the strongest form of routing guidance.

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