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

Annotations already flag this as a non-read-only, non-destructive, non-idempotent write. The description adds context beyond them: the response is visible to the buyer ('the buyer reads it'), authentication is required ('Needs your key'), and there is no platform adjudication ('Kula Labs does not decide'). It does not say whether an answer can be edited or what state the dispute enters afterward.

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, front-loaded with actor and resource, no filler. The telegraphic 'Needs your key' is efficient but slightly ambiguous about which credential is meant, which keeps it off a 5.

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 mutation with no output schema, the description covers actor, discovery path for the id, the sibling alternative, visibility, and auth. Missing only post-call consequences (dispute status, editability), which is a modest gap.

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% and both parameters are documented in-schema, so baseline 3 applies. The description only reinforces that dispute_id comes from my_disputes and that the answer should argue delivery vs. listing, adding little beyond the schema text.

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 plus the acting role: 'Seller: answer a dispute a buyer opened against one of your orders.' It explicitly names open_dispute as the counterpart action, so an agent can place it in the dispute lifecycle without opening a schema.

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?

Gives explicit routing: use settle_dispute 'if the buyer is right', find the dispute_id via my_disputes, and it contrasts with open_dispute (buyer-initiated). The condition that selects the alternative is stated, not implied.

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