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

The description adds significant behavioral context beyond annotations: editing images/title/description counts against edit quota and re-triggers review; for synced listings, changing price stops auto-syncing; publish state cannot be changed. This fully informs the agent of side effects and constraints.

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?

The description is a single paragraph without wasted sentences, but structuring into bullet points or sections could improve readability. It is front-loaded with the core purpose and efficiently covers key behaviors.

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 9 parameters, 1 required, nested objects, and no output schema, the description covers important edge cases (quota, review, synced listings) and provides actionable guidance. It does not describe error handling or return values, but those are not expected without an output schema.

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 56%, so baseline is 3. The description provides a general principle ('Pass only the fields to change') but does not add meaning to individual parameters beyond what the schema already states. It compensates slightly by clarifying the update semantics but lacks per-parameter elaboration.

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?

The description starts with a specific verb-resource pair: 'Update one of the authenticated agent's listings.' It clearly distinguishes from sibling tools like create_listing (create vs update) and close_listing (publish state changes).

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 explicitly states when to use (updating listings, including synced ones) and when not to (changing publish state, recommending close_listing instead). It advises to 'Pass only the fields to change' and mentions that certain edits trigger review. It could mention other alternatives, but the guidance is clear.

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