findEmbeddingIndexes

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

Annotations already declare a safe read (readOnlyHint=true, destructiveHint=false, openWorldHint=false), so the bar is lower. The description adds useful behavioral detail beyond that: the enumerable status lifecycle values (pending|indexing|ready|error) and the intended dedupe-check usage pattern.

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, front-loaded with the core action and followed by the field list and the pre-flight check. No redundant or filler text.

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?

A zero-parameter read tool with full annotation coverage and an output schema; the description supplies everything an agent needs to decide when to call it and what it will see, without duplicating return-value documentation.

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 there is no argument semantics to explain; baseline 4 applies. The mention of label+propertyName refers to index attributes referenced elsewhere, not to inputs here.

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 verb and resource ('List all embedding index policies configured for the current project') and enumerates the returned fields, which clearly separates it from createEmbeddingIndex/deleteEmbeddingIndex/getEmbeddingIndexStats. It never names a sibling explicitly, so differentiation is inferable rather than stated.

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?

Gives an explicit call condition: 'Call this before creating a new index to check if one already exists for the same label+propertyName.' That is actionable pre-flight guidance, though it offers no when-not-to-use or alternative tool routing.

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