update_menstrual_daily_log

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

Adds substantial behavior beyond the annotations: it discloses that the operation is a full-day replace (destroying unrelated existing fields), enumerates an error condition (no optional field -> GarminError), and documents the load-bearing undefined-vs-empty-string distinction for notes plus a discharge value constraint. This is exactly the destructive/auth/edge-case context annotations cannot carry.

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?

Dense but front-loaded with the highest-stakes fact (full-day replace) and every clause carries distinct information about errors or edge cases. The semicolon-packed formatting is slightly run-on, but there is no 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?

For a destructive nested-object mutation with no output schema and no annotations beyond the safety hints, the description covers the behavioral essentials an agent needs (replace semantics, required-field rule, notes/discharge edge cases, irreversibility). Remaining gaps are the undocumented option fields and the absence of any return-value mention.

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 50% (only calendarDate is documented; the eight nested option fields are bare). The description meaningfully compensates for two of them: it explains notes semantics and the NO_DISCHARGE exclusivity rule, both of which are impossible to infer from the schema. It does not cover flow, moods, symptoms, etc., so it does not fully close the gap.

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 never states plainly what the tool does (e.g. 'updates the menstrual daily log for a date'); it opens with behavioral policy ('full-day replace, not a merge'). The verb+resource is only inferable from the tool name, and there is no differentiation from siblings like update_menstrual_calendar or init_menstrual_cycle_setup. Adequate but the purpose itself is under-specified.

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 strong operational guidance: at least one optional field is required or it errors, the call is irreversible, and the agent should confirm with the user first. It does not, however, say when to prefer this over sibling write tools, so it stops short of full when/when-not coverage.

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