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

Annotations already cover read-only, idempotent, non-destructive behavior, so the bar is lower. The description adds meaningful context beyond annotations: prices are approximate typical retail values rather than live quotes, and the ranking is predetermined so whole foods appear cheaper than all powders including KABO's.

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-loaded with the core action, units, and ordering, followed by a usage example and an important price caveat. The KABO's clause is somewhat promotional and arguably expendable, but the description remains compact and readable.

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 one-parameter ranking tool with no output schema and full annotation coverage, the description provides the metric, source scope, ordering, inclusion list, and price caveat. A brief note on the return shape or budget filtering would make it fully self-contained.

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?

The single optional budget_inr parameter has 100% schema description coverage, including its ceiling semantics. The description adds no parameter-specific information, which is acceptable given the schema fully documents it.

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 — rank protein sources by cost in rupees per 10 g of protein, cheapest first — and enumerates the included sources. This is clear enough to distinguish from lookup_food or compare_foods, but it never names or contrasts those siblings explicitly.

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 one concrete usage context: answer 'cheapest way to get protein in India'. It does not say when not to use it, nor does it route the agent to compare_foods, lookup_food, or protein_target for related questions.

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