prepare_replay

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

No annotations are provided, so the description carries the full disclosure burden. It valuably discloses caching/idempotency behavior ('if not already cached'), but it omits whether the operation is long-running, whether it consumes replay quota, what side effects it has on the session, and what permissions are needed. Given a sibling get_replay_quota exists, the silence on quota consumption is a meaningful gap.

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?

Two sentences with no filler; the core action is front-loaded and the readiness pointer is neatly appended. Nothing could be removed without losing information.

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 single-parameter tool with no output schema, the description covers the action and the follow-up check, which is the minimum an agent needs. It is thin on the operational side of a state-changing preparation step: duration, quota cost, and whether the artifact persists remain unstated and are not covered elsewhere in structured fields.

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 100% and the single sessionId parameter is already documented in the schema with its source tools. The description adds no further meaning about the ID. Baseline 3 applies when the schema does the work.

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 gives a specific verb and object: prepare a session for recorded playback, with a clarifying clause about generating the playback artifact when not cached. That is enough to separate it from get_replay_status and list_replay_sessions in the sibling set. It stops short of 5 because 'prepare' alone is somewhat abstract and the exact output of the preparation is only implied.

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 points to get_replay_status for the readiness step, implying a prepare-then-check workflow, which gives useful context. However, it never states when to call this versus when it is unnecessary, nor whether repeated calls are expected or how it relates to the quota tooling. The guidance is 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.