quick_add_food

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

Annotations cover the safety profile (readOnlyHint=false, destructiveHint=false, openWorldHint=true), so the bar is lower, and the description still adds real behavioral context: the Connect+ subscription gate and the check-with has_connect_plus path. It doesn't describe failure modes beyond the schema's 400 note, keeping it from a 5.

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-loads the subscription requirement and packs endpoint, entry shape, and type into a compact block with little waste. The trailing "Needs Connect+" repeats the opening sentence, a minor redundancy that costs it a point.

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 write tool with annotations covering safety and no output schema, the description supplies the subscription gate, the endpoint, the entry semantics, and a pointer to logFood for meal rules. Required fields are enumerated, and the nested schema handles meal/time defaults, so little 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?

Top-level schema coverage is reported at 0%, but the nested input object does document date, meal, and time, and the description restates the required name/macro set. It adds the 'no food behind it' meaning but no format or default detail beyond what the nested schema already carries, so a baseline 3 is appropriate.

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 and resource ('an entry by name + calories/carbs/protein/fat with no food behind it'), and the 'QUICK_ADD ... no food behind it' phrasing meaningfully distinguishes it from log_food (which logs an existing food). It stops short of naming the sibling it contrasts with, so it lands at clear-but-not-fully-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?

Provides one concrete prerequisite ("Requires a Garmin Connect+ subscription (check with has_connect_plus)") and defers meal rules to logFood, which implies a usage context. However it never states when to pick this over log_food or create_custom_food, so the when-versus-alternative guidance is only implied.

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