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

Annotations already signal readOnlyHint=false, destructiveHint=false, and idempotentHint=true. The description adds value beyond these: editing is free (no credit charge), field-specific moderation re-trigger (returns to 'pending'), price/currency-only edits stay live, and possible rejection when price is locked. No contradiction with annotations; the price-lock rejection is state-dependent, not idempotency-violating.

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?

A single dense paragraph with front-loaded purpose. Every sentence earns its place — ownership constraint, fixed fields, pricing, and side-effects are all valuable. Slightly long, but the complexity of side-effects (moderation, price lock) justifies the length.

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?

Given the output schema exists, omitting return-value details is acceptable. The description covers the operational essentials: ownership, fixed fields, costing, moderation side-effects, and rejection conditions. The main gap is the undocumented 'details' parameter and a missing hint about set_listing_status/update_listing_images as related mutations, but overall it is near-complete for a complex mutation.

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 only 14%, so the description carries significant burden. It adds behavioral meaning to title/description/location (moderation re-trigger) and price (lock rejection), which helps agents choose values. However, the 'details' parameter is never mentioned, and listing_id semantics are only implied as the identifier — an incomplete compensation for the low schema coverage.

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 (edit) and resource (one of the USER'S OWN listings) with the identifier (listing_id) and the exact editable fields (title, description, price, currency, location). Clearly distinguishable from siblings like create_listing (new) and update_listing_images (images only).

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?

Provides clear context: only the owner can edit, and vertical/intent_type/role are fixed with an explicit redirect ("publish a new listing to change those"), implicitly routing to create_listing. It notes editing is free (no credit charge) versus likely charged creation, but does not explicitly name sibling alternatives or state when not to edit.

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