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

Annotations flag idempotentHint=true and destructiveHint=false; the description corroborates and enriches this by explaining the existing-draft case (returns draft unchanged, never overwrites, draftKept flag) and that changes must be made in the app. It does not cover auth/rate-limit specifics, but the mutation semantics and non-destructiveness are fully disclosed.

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?

Front-loaded with the core action and the return payload, which is the right ordering. It runs long as one dense paragraph with some restatement ('changes are made in the app' / 'publishing happens in the app'), which slightly dilutes rather than wastes.

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?

Despite having no output schema, the description explains the return payload (review/publish link, eBay connection status, connect link, draftKept) and the follow-on user flow. For a 4-parameter mutation with only one required field, nothing an agent needs to call and interpret it correctly is missing.

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 100%, so the schema already carries per-parameter meaning including defaults and the 'not applied when a draft exists' caveat. The description only echoes the field list and the market-price default, adding no new syntax or precedence detail beyond structured data.

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 precise transformation chain: photo scan from price_item (account.scanId) → inventory item with a draft eBay listing containing title, price, condition, description. This is a specific verb+resource with the upstream dependency named, which cleanly separates it from price_item and the other read-oriented siblings.

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 the precondition (signed-in user, scan_id from price_item), the boundary (never publishes — publishing happens in the app after user review), and the alternative path for the not-connected case (connect link returns them to the same item). An agent knows both when to call it and what it must not expect from it.

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