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

Goes well beyond the readOnly/idempotent annotations: it says prices are computed without a model from vendor pricing pages, enumerates the per-tool outcome states (cheapest fitting plan, or unknown/ineligible/contact sales/stale) with the important guarantee that unknown is never rendered as missing or free, and discloses the free tier and a sixty-per-day-per-address rate limit. It also states nothing is persisted.

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?

Front-loaded with what the tool does and how, followed by return semantics, persistence, and limits — a sensible ordering with no filler sentences. The em-dash reason-code list is dense but functional; phrasing is slightly compressed in places.

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 nested-parameter, enum-bearing comparison tool with an output schema, the description supplies everything an agent needs: inputs framing, computation trust model, return shapes and failure states, side-effect profile, and quota. Nothing material is left for the agent to guess.

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 the description only needs to reinforce, and it does so lightly by naming the scenario components (seats, minutes a month, required capabilities) and the 2-5 tool bound. It adds no currency-conversion or per-recording-cap nuance beyond what the schema already documents, 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?

States a specific verb and resource — 'Preview a price comparison of 2-5 Atlas tools for a usage scenario' — with the scope (2-5 tools), the domain (AI transcription seats/minutes/capabilities), and the computation basis. It also distinguishes itself from atlas_dataset, which is the sibling that persists results.

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?

Makes clear this is a preview/exploratory call ('Nothing is saved; atlas_dataset keeps it for a website'), which effectively names the alternative and when to prefer it. It does not explicitly exclude adjacent cases, such as looking up a single tool's pricing via atlas_lookup or resolving domains via atlas_search (the latter only appears in the schema).

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