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

Annotations already cover safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description adds useful state semantics ('with progress while it runs and the error when it failed'), though it doesn't say whether processing is asynchronous, how fresh the status is, or whether completed is terminal.

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 tight sentence that front-loads the verb and resource, with state enumeration and progress/error notes in a compact clause. No filler; could only be marginally tighter with explicit routing.

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 one-parameter read-only status tool with a fully described schema, the description covers the value space, progress reporting, and failure errors. With no output schema, an explicit note on what a 'completed' status implies for follow-up actions would close the remaining gap.

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 parameter description already tells the agent where the ID comes from. The description adds nothing about the dataSourceId beyond what the schema states, so baseline 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?

Names a specific verb and resource ('Check one knowledge source's indexing status') and enumerates the possible states. Clearly distinguishable from siblings like list_sources (enumeration) and get_analytics (metrics).

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?

Implicitly the right tool after starting an indexing job, but the description gives no explicit when-to-use guidance or points to alternatives such as list_sources for discovering the ID. Usage is inferable rather than stated.

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