Index Recording

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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the agent knows this writes/overwrites something. The description usefully identifies the written artifact, but it omits operationally important facts: that OCR is expensive, that results are cached (only visible in the force parameter's schema text), and what gets overwritten when an index already exists.

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 with no filler; the artifact and the downstream purpose both come immediately.

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 an output schema present, return values need not be explained, and the six parameters are fully documented in the schema. The remaining gap is behavioral: cost, caching and overwrite semantics are not addressed despite destructiveHint=true.

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 every parameter including force, maxFrames, transcript and sceneThreshold is already documented. The description adds no parameter-level meaning beyond what the schema provides, so the baseline of 3 applies.

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?

A specific verb ('Build') and resource ('a recording's text timeline'), including the concrete artifact name (<video>.index.json) and its contents. It also names the downstream consumer, search_recording, which helps separate it from neighbors like transcribe or read_events, though it doesn't explicitly contrast with those siblings.

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 phrase 'for search_recording' implies this is a prerequisite for searching, but the description never says when to use it versus alternatives such as transcribe or chapters, nor when not to run it. Usage is implied rather than stated.

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