write_day_note

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

Annotations already flag destructiveHint=true and openWorldHint=true, and the description adds substantial context beyond them: omitted fields preserve existing values, null clears a field, a note with no tag and no text is removed entirely, and the note suppresses the missed-workout nudge and reminder. The openGym merge/sync rules further disclose concurrent-update behavior.

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?

Purpose and mutation semantics are front-loaded, but the final openGym sentence is long, dense, and reads as tangential general app behavior rather than something specific to writing a day note, diluting the focus of an otherwise efficient definition.

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 mutation tool with no output schema, the description covers what an agent needs: the update/removal semantics, the downstream effects (nudges, reminders, calendar display), and the sync-merge caveat. Nothing essential to correct invocation appears missing.

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?

With only 33% schema coverage, the description compensates well: it explains the partial-update contract ('a field left out keeps what the note has; null removes it') and enumerates the valid tag values (sick, travel, rest, injured), which maps to the enum. The text field's 500-char limit is not restated but the schema covers it.

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+resource (write a note on why a day had no training) and enumerates the note tags. It clearly conveys what the tool does, though it never names the sibling (write_day_plan) it sits beside, so sibling differentiation is left implicit.

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?

Implied usage is present: a note excuses a day, the app offers a new note only on a day without a workout, and leap permits it. However, there is no explicit when-to-use vs when-not-to-use guidance or named alternative, so the agent must infer the selection conditions.

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