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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint=false, so the side-effect profile is covered. The description adds genuinely useful context beyond that: the tool is deterministic arithmetic and performs no clinical validation, which steers agents away from treating the output as a safety check. It does not cover error behavior (e.g., water_ml or vial_mg bounds).

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 sentences, front-loaded with the identity of the tool and its inputs, followed by the output list and the scope caveat. No filler or redundancy.

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 what is returned, which is the main thing an agent needs. Minor gaps remain around rounding conventions and boundary/error behavior, but the definition is complete enough to call the tool 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 description coverage is 100%, so the schema already documents every parameter and the enum. The description restates vial_mg, water_ml, and dose with their units but says nothing additional about semantics, and never mentions dose_unit explicitly. 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?

The description names a precise verb and resource ('Reconstitution arithmetic') and enumerates the computed outputs: concentration, dose volume in mL, U-100 syringe units, and doses per vial. An agent can immediately tell this is a pure calculator, distinct from the sibling vendor/sourcing tools.

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?

The scope limitation ('pure math; it does not judge whether a dose is appropriate') tells the agent what it will not get, but there is no explicit when-to-use framing or routing to an alternative such as get_dosing_guide for clinical judgment. Usage is implied rather than stated.

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