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

Annotations already declare the mute profile (readOnly=false, destructive=false, idempotent=false), so the bar is lower. The description adds one genuinely useful behavioral fact beyond annotations: both parties must confirm, i.e., a proposal alone does not execute a trade. It does not disclose auth handling (key vs Authorization: Bearer) or what a repeated call does, given idempotentHint=false.

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?

Very short and front-loads the WHEN/alternative routing, which is the highest-value information. It wastes a little space restating the tool name at the start and on an example that merely echoes a schema field, but there is no filler prose.

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 an output schema present and full schema descriptions, the description need not explain returns or parameters. But this is a non-idempotent mutation with a multi-step resolution flow (accept/counter/decline), and the description never says what state a proposal lands in or who acts next, leaving the agent to infer it from sibling names.

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 all six parameters are already documented in the schema. The description adds nothing beyond a tautological example call repeating the required 'to' field. Baseline 3 is appropriate when the schema carries the semantics.

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 concrete action: proposing a direct bot-to-bot swap that requires both parties' confirmation. It also names the two sibling tools it is not (bazaar_create_listing, bazaar_submit_offer), so an agent can place it in the trade flow. It stops short of a crisp verb+resource phrasing beyond the tool name itself, and does not say a proposal creates a pending object resolved by booth_accept/booth_counter/booth_decline.

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?

Explicit 'WHEN' clause plus two named alternatives with their distinguishing traits (public listing vs offer on a listing). That is real routing guidance rather than implied usage. It lacks an explicit 'when not to use' (e.g., do not use to respond to an existing proposal — use booth_accept/counter/decline).

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