Write a journal entry or check-in

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

The description is rich in behavioral detail, but it directly contradicts the annotations: it warns that mode 'replace' REPLACES that day's whole journal body, while annotations declare destructiveHint=false. Additionally, 'append' mode is not idempotent, conflicting with idempotentHint=true. This is a clear annotation contradiction, so the score must be 1.

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?

The description is longer than typical but nearly every sentence earns its place by conveying a non-obvious constraint or warning. The 'WRITES.' opener is slightly redundant with 'Saves', but the information is front-loaded and well organized with an 'IMPORTANT' flag.

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?

Given the complexity of this write tool, the description covers the critical input semantics, mode selection, check-in validation, and tone guidance. The main gap is that no output schema exists and the description does not state what the tool returns on success or failure, leaving that to runtime inference.

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?

Although schema coverage is 100%, the description adds substantial meaning beyond the schema: it explains the default replace behavior and when to append, warns that partial check-in fields are rejected, notes markdown conversion to HTML, and instructs the agent to write in the user's voice. This goes well beyond the parameter types and formats in the schema.

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 opens with a clear action verb ('Saves') and names the resource ('user's journal entry and daily check-in for one date'). It also distinguishes this tool from read-only siblings like goalslot_get_journal by emphasizing the write/upsert behavior and the replace/append modes.

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 gives explicit situational guidance: use 'append' when the day may already have content and the user did not ask to overwrite, and notes that partial check-in data will be rejected. It does not explicitly name alternative sibling tools, but the write-vs-read distinction and the append/replace rule provide strong usage direction.

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