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

Annotations already declare readOnlyHint=true, so safety is covered. The description adds genuinely useful behavior beyond the annotations: the null return when nothing is configured and the downstream consequence that the client app shows an automatic estimate, which matters for interpreting an empty 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?

Two sentences, zero waste, with the core definition front-loaded before the empty-result caveat. Every clause carries information an agent can act on.

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 single-parameter read with no output schema, the definition covers identity, scope, and the empty-result case. It does not sketch the shape of a populated result (which fields accompany the calorie/protein/carb/fat values), a minor omission given no output schema exists.

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% and the single clientId parameter is documented in the schema as the client's User _id from list_clients. The description adds no additional meaning about the identifier, so the 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 description names a specific resource (a client's daily calorie and protein/carb/fat gram targets) and explicitly scopes it as coach-set and 'independent of any plan', which separates it from plan-derived macro values. It stops short of naming the sibling tools that could be confused with it (set_client_macro_targets, clear_client_macro_targets, calc_macros), so it is clear but not fully sibling-differentiated.

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?

Usage is only implied: an agent can infer this is the read for coach-authored macro targets, and the 'independent of any plan' clause hints at when it applies. There is no explicit when-to-use versus when-not, no statement of prerequisites (e.g. coach permissions, client ownership), and no alternative named.

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