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

Annotations only cover readOnlyHint/openWorldHint; the description goes far beyond them, disclosing pricing ($0.02 flat, no token multiplier), the full x402 keyless payment handshake, where payment requirements and receipts appear (`structuredContent`, `_meta`), and retry-safety rules. This is exactly the context an agent needs to invoke correctly and avoid double-paying.

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?

Every sentence carries load — purpose, pricing, prerequisite, auth, payment flow, failure handling — so little is wasted. However, leading with a billing line rather than the purpose is slightly off front-loading, and the payment-flow passage is dense enough to slow a skimming agent.

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?

There is no output schema, so the description must carry the return story — and it does, covering the citation-bearing answer, the payment-required result, the retry receipt location, and terminal 409/502 outcomes. Nothing needed to call it successfully is missing.

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 schema already documents all four parameters, and the description adds essentially no per-parameter detail beyond the URL-template mapping. Baseline 3 is the correct ceiling when the schema does the heavy lifting.

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 — 'Ask a question of a collection and get a generated answer with citations' — and reinforces it with the exact underlying route POST /v1/collections/{collectionId}/query. That resource scoping (a collection, not a channel) cleanly distinguishes it from the sibling query_channel.

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?

It gives the prerequisite ('Query a collection once `get_status` says completed'), the required auth scope ('the key's `query` scope'), the keyless constraint, and routes to the sibling `quote` for exact pricing. It also names failure conditions with explicit follow-up rules ('never pay again after a 409 or 502').

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