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

Goes well beyond the annotations (readOnlyHint=false, openWorldHint=true) by disclosing cost ('Free'), auth requirements (API key with write scope), the underlying POST endpoint, and critically that the `collection_token` is shown once and absent on an idempotent replay. It also clarifies that prices are service defaults and `quote` gives exact pricing.

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?

Dense and front-loaded, with the key operational facts (cost, purpose, auth, token handling) stated up front. It packs several distinct facts into a few sentences, which borders on terse, but no sentence is filler.

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?

With no output schema, the description carries the return-value burden itself and does so: it names the returned collection and the one-time `collection_token`. Auth, cost, idempotency behavior, and follow-up workflow are all covered, so an agent has everything needed to call and handle the response.

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%, so both parameters are already documented, which sets a baseline of 3. The description adds meaning the schema lacks: the idempotency key's observable effect (token absent on replay) and that pricing isn't specified per-call. It doesn't explain the title parameter, but the schema fully covers it.

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 ('Create an empty collection') and immediately distinguishes it from the sibling that populates it ('add sources to later with `add_sources`'). An agent can tell this apart from add_source/add_sources without opening a schema.

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?

Explicitly positions the tool in a workflow: create the empty collection first, then add sources with `add_sources`. It does not state when NOT to use it (e.g. versus quote or query_collection), but the sequencing guidance is clear enough for correct selection.

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