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

Annotations only cover the safety profile (readOnlyHint=false, destructiveHint=false, openWorldHint=true), and the description adds substantive behavior beyond them: notes are additive and never overwrite, the call returns the note with its id, and it requires OAuth sign-in with a LuxAlgo account. That is exactly the extra context an agent needs before invoking.

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-loads the action and scope in the first clause, then routes to alternatives. It is dense but every clause carries information; the docs URL and OAuth note are mildly incidental but not padding.

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?

There is no output schema, yet the description covers the return value ('the note with its id'), the write semantics, the auth prerequisite, and the sibling routing. Nothing an agent needs to call this correctly is 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?

Schema coverage is 100%, so the schema already documents date, body, and context, making 3 the baseline. The description adds real meaning for `date` by clarifying it may be any day, traded or not, and reiterates the journal-timezone YYYY-MM-DD format — useful for a date the agent might otherwise assume must correspond to a trade.

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 ('Add a new note to a trading day') plus the scope qualifier 'any day, traded or not', which an agent cannot infer from the name alone. It explicitly separates itself from journal_update_note and journal_update_trade's notes, so the sibling boundary is 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?

Gives explicit when-to-use routing: this tool for creating, journal_update_note for changing an existing note, and journal_update_trade's notes for a note tied to a specific trade. It also states the non-exclusion ('days hold any number of notes, so this never overwrites'), removing the main ambiguity about whether a day can hold multiple notes.

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