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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds genuine behavioral context beyond that: it discloses returned precision/parallax warnings, syringe overflow checks and concentration advisories, plus the 'Research use only' domain caveat. It does not describe error behavior, but the added disclosure is substantive.

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 purpose, then modes, then return characteristics, then the disclaimer — every sentence carries information. It is slightly dense with four clauses but no wasted wording.

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 compensates by naming what is computed and what warnings come back, which is what an agent needs to interpret results. A calculator with all parameters documented needs little more, though error/edge-case behavior (e.g. invalid dose/water combos) is left implicit.

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 100% and the schema itself already labels dose_mcg as forward mode and dose_units as reverse mode, so the description's mode explanation largely restates structured data. Baseline 3 is appropriate since the schema carries the parameter burden.

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 (calculate) and resource (peptide reconstitution) and enumerates the exact outputs — concentration, draw volume, syringe units, doses per vial. It also splits the tool into forward and reverse modes, making it unmistakably distinct from planning-oriented siblings like plan_schedule and compare_syringes.

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 explicit mode-selection guidance — pass dose_mcg for forward mode, pass dose_units to back-solve the dose — which tells the agent when to supply each parameter. It does not name an alternative sibling tool or state exclusions, so it stops short of the 5 bar.

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