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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds one genuinely useful behavioral signal, 'Estimates only', which sets accuracy expectations, but says nothing about portion ambiguity, accuracy limits, or what happens with unrecognized meals or unsupported languages.

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 short sentences, front-loaded with the core capability and immediately followed by the scoping example. Minor redundancy in 'Estimates ... Estimates only', but the hedge earns its place as a caveat.

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 usefully enumerates the returned values (calories, protein, carbs, fat), which is the key missing piece an agent would otherwise lack. The undocumented 'language' parameter keeps it from being fully complete for a two-parameter 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 description coverage is 0%, so the description must carry the burden. It does explain 'meal' well via the portion-plus-example phrasing, but the second parameter, 'language', is never mentioned or explained in the description, leaving a real gap.

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 (estimates) and resource (calories/macros for a described meal), and gives a concrete example ('2 idli with sambar and coconut chutney') that pins down the expected input granularity. It does not differentiate itself from nearby tools like health_calculators, so it falls short of 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?

Usage is only implied: the description makes clear it applies when you have a described meal or portion, but it never states when to prefer an alternative (e.g. health_calculators) or when not to call it. 'Estimates only' is a caveat, not routing guidance.

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