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

Annotations already declare destructiveHint=true and idempotentHint=true, but the description adds real value beyond them: partial-update semantics (omitted fields unchanged), null-clears-an-optional-field semantics, an optimistic-concurrency token, the required catalog:write OAuth scope and connected account, and account tier limits. It stops short of saying what happens on a stale updatedAt conflict or which fields are the destructive ones.

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 short sentences, front-loaded with the action and scope, then the prerequisite, then edit semantics, then environment requirements. No sentence is redundant and nothing is buried.

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?

An output schema exists, so return values need no explanation, and the description covers the auth, scope, tier, concurrency, and partial-update dimensions an agent needs before calling a destructive mutation. The one real gap is conflict behavior when expectedUpdatedAt is stale, which matters for a tool with destructive and idempotent hints set.

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 0%, so the description must carry the load, and it does explain the two highest-risk parameters conceptually: expectedUpdatedAt (take it from the read) and the null-vs-omitted convention that governs price, description, and privateNote. It adds nothing about individual field constraints or the meaning of hidden, so half the parameter surface is only defined by type and bounds in the schema.

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?

"Edit one owned listing" gives a specific verb (edit) and resource (listing) plus an ownership scope that separates it from read tools like get_listing and from the creation path create_listing. It does not explicitly name the nearest sibling (update_list) or state that it cannot touch other users' listings, but the intent is unambiguous.

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 description establishes a clear workflow prerequisite ("Supply the updatedAt value from the listing read"), which tells an agent to read before writing. It also defines the two field-editing modes. It lacks explicit when-not guidance or a pointer to alternative tools for bulk/other edits, so it stops short of full routing guidance.

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