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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so 'read-only and changes nothing' is largely redundant. What the description adds beyond the structured fields is the authorization requirement ('Needs the manage token') and the scope of the view (seller-side vs public), which the annotations do not convey. It does not discuss rate limits or error behaviour, so it stops short of a 5.

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?

Three tight sentences: what it returns first, then the sibling routing, then the safety/mutability note. No sentence is filler, and the most decision-relevant content (scope and returned fields) is front-loaded.

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 two-parameter read tool with an output schema, annotations and full schema coverage, the description supplies the remaining unknowns: auth requirement, seller-side vs public scope, mutability, and sibling alternatives. An agent has everything needed to select and invoke it correctly.

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% and both parameters are fully documented in the schema (including the bearer-token secrecy note), so the description adds no parameter syntax or format detail beyond it. Baseline 3 is appropriate when the schema carries the parameter burden.

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 (Read) and resource (a seller's own view of one listing), then enumerates the concrete contents returned: terms, payment DNS state, proceeds, checklist, orders. It also explicitly names what it is not (the public buyer-facing quote, the term-setting tool), so an agent can distinguish it from quote_domain_purchase and set_listing_terms without opening schemas.

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?

Names two alternatives and the condition that selects each: use quote_domain_purchase for the public buyer-facing quote, set_listing_terms to change price or floor. It also states the prerequisite (needs the manage token), which is precisely the routing information an agent needs.

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