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

Annotations already declare readOnly/idempotent/non-destructive and closed-world, so safety is covered. The description adds real context beyond that: results are anchored to cited evidence and include licensed doses for the drug, and empty-medication calls dump the whole table.

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 front-loaded sentences; the core function and the distinguishing "eats less, not loses weight" point come first. The "This is the site's original data" clause is slightly promotional but earns its place as a provenance signal.

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 must carry return-value semantics; it partially does (evidence, licensed doses) but leaves open the response shape and the doseMg-only or out-of-range-dose cases. Adequate but with clear gaps for a two-parameter lookup tool.

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 50%; the medication parameter is well documented in-schema (generic-to-brand mapping), but doseMg has no description anywhere. The description adds the no-medication behavior but never explains doseMg units, ranges, or what is returned when a dose is unlicensed or omitted.

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 (appetite suppression factor per medication/dose) and explicitly contrasts it with the weight-loss framing, so an agent knows what it returns. It does not differentiate from the listed siblings (calculate_glp1_target, search_foods), which keeps it below a 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?

"Call with no medication to get the whole table" gives concrete invocation guidance for the degenerate case, and the statement about appetite vs. weight loss clarifies when this tool is the right lens. No exclusion or alternative-selection advice against calculate_glp1_target is given.

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