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

Annotations only cover the safety profile (readOnly=false, destructive=false, openWorld=false), so the description carries the rest and does so well: it discloses the date/time defaults, that reminders require a time, and that repeat spawns future-day tasks automatically rather than requiring repeated calls. It stops short of describing the return value or permission requirements.

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?

Three dense sentences with the defaults front-loaded and the highest-risk guidance (the repeat warning) last. Every clause carries information, though the final sentence is run-on and slightly harder to parse than necessary.

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 an 8-parameter create tool with no output schema, the description covers the parameters most likely to be misused (date, time, remind_minutes_before, repeat) and their interactions. The straightforward fields (title, sphere, starred, description) are left to the schema, which is reasonable and only a minor gap.

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?

Beyond the 63% schema coverage, the description explains the defaulting behavior for date and time and the cross-parameter constraint that remind_minutes_before only works with a time, plus the semantics of repeat. It says nothing about sphere, starred, or description, which are the remaining undocumented parameters.

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 verb+resource are explicit ('Add a task to a day') and the description immediately scopes the operation with date/time defaults, so an agent knows exactly what is created. It never distinguishes itself from siblings like add_subtask or add_goal, but the resource naming is specific enough to be 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?

It gives concrete conditional behavior: no date means today, no time means the untimed list. For repeat it explicitly says one call is enough and warns 'never add the same task to several dates instead,' which is a genuine when/when-not rule. It does not point to alternative tools, so it stops short of a 5.

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