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

Annotations already declare readOnlyHint=false, indicating a write operation, and the description adds behavioral context: the note appears under 'Upcoming' and has no money attached. This goes beyond the annotations, but it does not disclose side effects, idempotency, or what happens if the date is in the past. The description adds some value without contradicting annotations.

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 a single concise sentence that front-loads the core purpose ('A dated note under Upcoming') and then adds examples and a differentiator. It wastes no words and is easy to scan. Slightly more detail on parameters would be helpful, but the structure itself is efficient.

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?

The tool has 3 parameters, 2 required, and no schema descriptions. The description does not explain the meaning of 'title,' 'date,' or 'note' clearly enough for an agent to populate them correctly without additional inference. While an output schema exists, the input guidance is lacking, making the description incomplete for a reliable call.

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 explain the parameters. It only hints at 'date' and 'note' via 'dated note' and examples, but does not clarify the 'title' parameter or the exact format of 'date' and 'note.' The examples show note content (renew passport, cancel trial) but not the title. This is insufficient given the lack of schema descriptions.

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 states a clear action: it adds a dated note under the 'Upcoming' section, with examples of typical use (renew passport, cancel trial). It differentiates from monetary tools like add_planned_expense by explicitly saying 'No money attached.' While not as explicit as 'creates a reminder,' the verb 'add' is implied by the context.

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 implies usage for non-monetary dated notes through examples and the 'No money attached' note, but it does not explicitly state when to use this tool over alternatives like add_planned_expense or add_recurring_rule. It provides context but no exclusions or explicit guidance on selection criteria.

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