index_status

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so safety is covered. The description adds useful behavioral context beyond that: it reports whether any subsystem failed, warning the agent not to rely on a silently broken index. It stops short of describing polling frequency or consistency guarantees, but it meaningfully extends the annotation profile.

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?

Three sentences, each earning its place. The core purpose is front-loaded, the polling instruction follows naturally, and the failure-detection note is a useful final clause with no wasted wording.

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 no-parameter status tool with a dedicated output schema, the description provides everything needed: what it reports, when to call it, and the failure-detection guarantee. Return-value details can be left to the output schema.

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 zero parameters, so the baseline is 4. There are no parameter semantics to clarify, and the schema coverage is already 100% for the empty object.

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 states a specific verb and resource: it reports whether the index is ready, how many files/chunks it covers, whether indexing is running, and whether subsystems failed. It also names sibling tools (index_update, index_rebuild) in a way that distinguishes this status tool from the mutation tools.

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?

Usage is explicitly framed: poll this after calling index_update or index_rebuild to know when the work finished. The description leaves no ambiguity about when this tool is appropriate, and it names the specific triggering siblings.

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