Edit one of your listings

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

Adds real context beyond the readOnlyHint=false/destructiveHint=false annotations: sold listings are locked while a sale is live, updates are partial (only passed fields change), null clears auto-accept/decline rules, and GLONGUS_API_KEY is required. It does not disclose whether the lock is time-based, what error a locked listing returns, or whether escrow/price edits are restricted after offers exist.

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?

Four compact sentences, front-loaded with the partial-update rule and followed by constraints, the null convention, and sibling routing. No sentence is filler.

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 12-parameter mutation tool with a nested parcel object and no output schema, the description covers the highest-risk facts: partial semantics, the sold-listing lock, null clearing, and auth. It leaves the nested parcel object and per-field constraints entirely to the schema, which is reasonable, but a note on price/escrow editability after an offer exists would close the remaining behavioral 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 description coverage is only 8% across 12 parameters, so the description must compensate — and it only does for two of them, explaining the null-to-clear semantics for auto_accept_cents and auto_decline_below_cents plus the overall partial-update rule. Ten parameters (title, description, price_cents, condition enum, parcel nested object, dispatch_window_hours, requires_shipping, location, escrow_hours, listing_id) get no guidance from the description; the schema enums and constraints carry them alone.

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 ('Change fields on one of your own listings') and immediately scopes it to ownership. An agent can distinguish it from create_listing and get_listing without opening the 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?

Explicitly routes off-market/on-market transitions to delist_listing and relist_listing, which covers the main sibling ambiguity. It does not contrast with create_listing or say when a full re-create beats an edit, but the critical alternative is named.

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