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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true. The description adds real context beyond them: the goals derive from account Settings, per-weekday variation is a tier-gated behavior, and a Cotlet API key with access to this app is required. Return format/pagination is unaddressed, keeping it out of 5 territory.

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?

Four sentences, each carrying distinct information (source, return fields, tier condition, auth requirement), with the purpose front-loaded. Slightly dense for a single-parameter read, but no sentence is 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?

There is no output schema, but the description enumerates the returned goals (calories, protein, fat, carbs), covers the parameter's conditional behavior, and flags the auth prerequisite. An agent has everything needed to call it 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 100%, so baseline is 3; the description earns above baseline by explaining *why* date matters (only Premium tiers have weekday-specific goals) rather than just restating the YYYY-MM-DD format. That tier-conditional semantics is not derivable from 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?

States a specific verb+resource ('Get daily goals') and enumerates exactly what is returned: calorie goal plus protein, fat and carbohydrate goals. The 'as set under Settings > Goals > Daily Goals' clause pins down the data source, cleanly separating it from siblings like fitatu_get_nutrition_summary or fitatu_get_diary.

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?

Gives conditional guidance for the one parameter: pass date when on Premium/Premium+AI where goals vary per weekday, otherwise the static goal applies. It does not name a sibling alternative or state an explicit when-not, so it falls short of full routing guidance.

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