bi_get_timeline

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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds meaningful behavior beyond the annotation: omitted bounds default to the last 24 hours, and a rangeless query returns empty spans. This helps an agent predict response behavior for edge-case invocations.

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 two short sentences with no filler: purpose is front-loaded, and the second sentence delivers the key default/edge-case behavior. Every clause earns its place, and the description stays compact despite covering an important behavioral nuance.

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 read-only tool with five well-documented parameters and no output schema, the description alongside the schema is largely sufficient: required parameter, default time window, and rangeless edge behavior are all stated. The return structure is only hinted at via 'buckets' and the raw-vs-shaped distinction, but nothing critical for a correct invocation is missing.

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 100%, so the schema already documents all five parameters. The description mostly restates the camera requirement and the default-window behavior already present in the startdate/enddate schema descriptions. It adds little semantic value beyond what the schema provides, so baseline 3 is appropriate.

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 clearly identifies a camera-specific activity timeline with motion/trigger/alert buckets, and the tool name supplies the 'get' verb. This is readily distinguishable from sibling tools like bi_list_alerts or bi_get_clip_info because it returns an aggregated timeline rather than individual alerts or clips. The '24-hour' phrasing is slightly tied to the default window, but the second sentence resolves that ambiguity.

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 the use case—querying camera activity over a time window—but never explicitly states when to choose this over sibling tools such as bi_list_alerts or bi_get_camera_snapshot. It provides useful parameter-level guidance about startdate/enddate defaults and rangeless queries, but not tool-selection guidance, so usage context is only implied.

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