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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered; the description adds genuine non-obvious behavior: role-dependent result sets, redaction of other buyers' handles, and the absence of floor/fee fields. It does not mention pagination or result ordering, which is the main remaining gap.

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?

Compact, with the behavioral detail front-loaded behind a WHEN label and a concrete empty-args example. The opening "Barter offers mine." is redundant with the name and title, a minor waste.

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 burden of explaining return content, and it does so by role, including the redaction rule. It is nearly complete for a two-optional-parameter read tool, missing only result size/pagination expectations.

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 (key, listing_id) are already documented in the schema. The phrase "offers on their listings" loosely hints that listing_id scopes to a single listing, but the description adds no syntax, auth precedence, or default behavior beyond that.

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?

"Barter offers mine" restates the name, but the WHEN clause specifies the resource view precisely: buyers get their own offers plus counters, sellers get offers on their listings. An agent can tell this is the self-scoped view of barter offers rather than a general listing, though the description never names how it relates to siblings like barter_offers or bazaar_check_my_offers.

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?

The WHEN clause gives context (buyer-side vs seller-side viewing), but it reads more as a description of what is returned than as a call-condition. There is no exclusion or explicit alternative named for the overlapping tools (barter_offers, bazaar_check_my_offers), so routing relies on the "mine" token in the name.

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