List Indexes

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

Annotations already declare readOnlyHint=true, so the safety profile is covered; the description adds value by disclosing that the response includes per-index configuration and readiness status. It doesn't mention pagination or result limits, which is a minor gap for a listing operation.

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, zero waste, with the core action front-loaded and the usage hint following. Every sentence earns its place.

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-required-param read-only listing with no output schema, the description covers action, payload contents, and usage context adequately. Missing only edge behavior such as what an empty project returns.

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 description coverage is 100%, so the two parameters (llm_model, llm_provider) are fully documented in the schema, and the description need not repeat them. At baseline 3 since the description adds no parameter meaning. Note the parameters are analytics-only and unrelated to filtering the listing, which the description never clarifies.

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 Pinecone indexes in the project") and adds the scope of the payload (configuration and readiness status). The word "all" implicitly separates it from describe-index, which fetches one index, though no sibling is named explicitly.

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?

"Use this to discover valid index names before calling other tools" gives a concrete trigger and sequencing guidance relative to the rest of the toolset. It stops short of naming which alternatives to prefer for other needs (e.g., describe-index for detail on one index).

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