create_time_entry

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

Annotations already carry the write/open-world/non-idempotent profile, and the description adds real behavioral facts beyond them: start_time is silently ignored unless an instance setting is enabled, and end_time is server-derived (read-only) rather than settable. It doesn't discuss side effects on work-package spent time or duplicate-entry behavior, but the key silent-failure mode is disclosed.

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?

Four short paragraphs with the purpose front-loaded and each following sentence introducing a distinct, non-obvious fact (duration format, conditional start_time, derived end_time, sibling routing). No filler or repetition of the schema.

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 10-parameter mutation with no output schema and 30% coverage, the description covers the trickiest inputs but omits what 'activity' should be (a sibling list_time_entry_activities exists and isn't referenced), what 'spent_on' expects format-wise, and what 'ongoing' toggles. The confirm/preview workflow is handled by the schema, so its absence here is acceptable, but the remaining gaps are material.

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 30% schema coverage, the description does the heavy lifting on the two hardest parameters: hours is an ISO8601 duration with 'PT8H'/'P1D' examples, and start_time is an ISO 8601 date-time with an enablement condition. It also explains why no end_time exists. Activity, spent_on, ongoing, and user remain undocumented in both places, so it doesn't fully compensate for the coverage gap.

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 opening sentence names a specific verb and resource ('Create a time entry') and the closing sentence differentiates it from the sibling create_time_entry_until by the exact condition that separates them (end time vs. hours). An agent can pick between the two creation tools from the description alone.

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 an explicit alternative and the condition selecting it ('Use create_time_entry_until to specify an end time instead of hours directly'), plus a runtime prerequisite for start_time ('requires the instance setting "allow tracking of start and end times"; ignored otherwise'). It stops short of stating when not to log time at all or noting the sibling that supplies valid activity values.

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