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

Annotations already declare readOnlyHint=false, destructiveHint=false and openWorldHint=false, so the write/safety profile is covered. The description usefully adds a behavioral rule beyond the annotations: IU is vit-D-only and is converted to µg at 40 IU = 1 µg. It says nothing about idempotency_key or how 'at' defaults, so it stops short of rich disclosure.

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?

Three short sentences, front-loaded with the action and then the two things an agent cannot guess (kind values, unit handling). Every clause earns its place and nothing is padded.

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 write tool with zero required parameters and no output schema, the description covers the dose-entry essentials but omits the timestamp parameter's format/default and the deduplication role of idempotency_key. An agent could call it correctly for the common case but would be guessing on retry-safety and timing.

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, and it does explain two of five parameters well: kind's allowed values and the ug/iu units with conversion. However, 'at' and 'idempotency_key' receive no explanation anywhere, leaving the two most non-obvious parameters undocumented.

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 and resource ('Log a supplement dose') that clearly separates it from the sibling log_feed, log_sleep, log_nappy and log_note tools. It does not explicitly name an alternative, but the resource noun alone makes the scope unambiguous.

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 description never says when to reach for this tool versus the other log_* siblings, nor does it state prerequisites such as needing an existing child profile. The kind enumeration is parameter detail, not usage guidance, so the agent is left to infer context.

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