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

The annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=true and openWorldHint=false, so safety and repeat-call behavior are covered structurally. The description adds the meaningful constraint that this is a passive recorder that never computes or recommends a dose, which is real context beyond the annotations, but it says nothing about what happens on a rejected or duplicate entry or how a bad value is handled.

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: the first front-loads what is stored, the second immediately bounds what the tool will not do. There is no filler and no repeated field names.

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 three-parameter logging tool with no output schema, the description covers purpose, the recorded payload, and the key behavioral limit. The only real omissions are the relationship to log_medication and any note on what a successful call returns or how the entry is identified afterward.

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 67%, so the schema already documents the enum for kind and the accepted formats and no-future constraint for time. The description only names units and type, adding nothing about defaults, format, or the meaning of 'mixed' beyond what the schema states, which matches the baseline when the schema does the heavy lifting.

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 specific verb and resource in the user's language ("Apunta la insulina") and scopes the payload to units and type, so an agent knows exactly what gets recorded. It does not explicitly distinguish itself from the nearest sibling, log_medication, which is the main thing keeping it from 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?

It states the operating condition clearly: record only what the person reports, with no dose suggestion or calculation. That is a useful boundary, but it gives no guidance on when to pick this over log_medication for an injectable, nor any prerequisites such as needing the kind before logging.

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