index_status

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

With no annotations supplied, the description carries the full burden and does state 'Read-only', which is the key safety fact for a zero-parameter tool. It also discloses the substance of the response - per-client sync state, approximate sizes, and detached run details including log tail - which goes beyond a bare label. It does not say whether the call fans out to remote clients or how costly/fresh the data is, so it stops short of a 5.

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 dense sentence with the safety qualifier front-loaded and the returned data grouped into logical buckets. The parenthetical enumerations are efficient rather than padded. Slightly telegraphic phrasing ('read, rows', 'rows/s') costs it a perfect score.

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?

There is no output schema, so the description must convey the return shape and does: sync state fields, approximate table sizes, and detached run status/metrics/log tail. For a zero-parameter read tool this is close to complete; only freshness, scope ('per client' semantics), and cost of the call are unaddressed.

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?

The tool takes no parameters (0 required, 100% coverage on an empty object), so there is nothing for the description to disambiguate. Baseline of 4 applies; the description correctly adds no redundant param discussion.

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 resource and enumerates exactly what the tool reports: index_sync state per client (last element id, backup time, rows), approximate table sizes, and detached runs with status, throughput, and log tail. This lets an agent distinguish it from the sibling action tool index_sync without opening either schema. The verb is only implied by 'Read-only', 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?

There is no explicit when-to-use or when-not-to-use guidance, and no sibling is named as an alternative. 'Read-only' weakly implies a safe diagnostic call, but the agent is left to infer that index_sync should be used to trigger work while index_status is used to inspect it.

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