Read the scene timeline

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

Annotations declare readOnlyHint=true and openWorldHint=false, covering the safety profile. The description adds the data source (OBS_TIMELINE_FILE) and the nature of the summarized content, but no behavioral traits beyond that (e.g., performance, pagination, auth). With annotations covering safety, this is a modest addition.

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?

A single, front-loaded sentence that packs the essential purpose and return content without filler. Every clause contributes to understanding what the tool does and returns.

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?

With no output schema and 6 optional parameters, the description carries the burden of explaining return values, which it does by enumerating the summary content (program scene durations, session offsets, live-at-time lookup). It does not cover edge cases or defaults, but the schema handles parameter specifics. Adequate for a read-only tool.

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% for all 6 parameters, so the schema fully documents each parameter. The description mentions time-based and stream-offset lookups but adds no syntax or format details beyond the schema. Baseline 3 is correct when the schema does the heavy lifting.

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?

States a specific verb ('Summarises') and resource ('scene timeline log'), and details the content returned (program scene, durations, sessions with offsets, live lookup). The resource is unique among the siblings, so an agent can distinguish it, but the description never explicitly names a sibling it is not, which keeps it from a 5.

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?

Provides use-case examples ('what was live at a given time or at a given second of a stream'), which implies when to use it. However, it does not state when not to use it, nor does it name alternatives like get_overview or list_scenes. Usage is therefore implied rather than explicit.

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