days_since_event

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

With no annotations, the description must carry the behavioral burden. It does convey that the operation is a pure calculation ('Return the number of days') and gives an example of an event name, but it does not disclose behavior for missing events, how timeline_state is read, or inclusive/exclusive edge cases.

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, front-loaded sentence with an illustrative example and no filler. It is as concise as possible, though it achieves that concision by omitting necessary detail.

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 a nested timeline_state object, no output schema, and no annotations, the description is under-specified. It omits the shape/meaning of timeline_state, the relationship between event_name and timeline_state, and failure behavior, so an agent lacks enough context to call it reliably.

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 only 33% (just reference_time is described), and the description does not compensate. It explains event_name only indirectly through 'named timeline event' and an example, while timeline_state remains completely unexplained – an agent cannot tell how event_name relates to the timeline_state object.

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 specific verb ('Return'), a resource ('number of days since a named timeline event'), and gives a concrete example ('surgery_date'). It is clearly distinct from the sibling tools, though it does not explicitly call out the difference.

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?

No guidance is provided on when to use this tool instead of alternatives such as extract_timeline_events or summarize_timeline_context. The intended use is only implied by the name and the 'since a named timeline event' phrase.

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