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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered for free. The description adds the return parameter set but omits behaviorally important facts for this variant of the tool, notably that CL and Vd cannot be computed without the optional 'dose'/'dose_unit' inputs, and gives no hint about unit conventions or handling of sparse/irregular time points.

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?

The piped keyword format front-loads the tool identity, then USE WHEN, ALIASES and RETURNS, so an agent can skim it quickly. The bilingual duplication is slightly redundant for a reader but serves retrieval matching, and no sentence is pure filler.

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 only four inputs and no output schema, the RETURNS line usefully stands in for a missing output schema by listing the produced metrics. However, the description never states that dose is what unlocks clearance and volume terms, nor what the response shape looks like, leaving a real gap for a tool whose main parameters are conditionally available.

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 four parameters (dose, dose_unit, time_points, concentrations) are already documented in the schema and the baseline of 3 applies. The description adds no meaning beyond the schema — it does not explain the optionality of dose or its consequence for CL/Vd, nor any length-matching requirement between time_points and concentrations.

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 opens with a specific verb+resource ('Non-compartmental PK (NCA)') and enumerates the exact outputs (AUC, Cmax, Tmax, t1/2, CL, Vd), which tells an agent precisely what computation this tool performs. It stops short of naming the nearest siblings (pk_pd_assess, pkpd_simulate, bioequivalence_compare) so the boundary against those is inferred only from 'non-compartmental' rather than stated.

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 'USE WHEN' clause gives a clear trigger condition: non-compartmental analysis of concentration-time data producing the listed parameters. There is no when-not guidance and no explicit alternative for compartmental modeling or PK/PD simulation, leaving the sibling routing to the agent's inference.

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