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

The annotations already signal destructiveHint=true, and the description enriches this by explaining the effect: buyers render the change immediately, the tool refuses if the file changed since review, and it refuses to create new live files. It also discloses the outbound approval rail: each call queues its own approval card, sends exactly once on approve, and has no standing grant. No contradiction with annotations; this is rich behavioral context beyond the flags.

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 longer than average but each section earns its place: the first sentence states scope, the second captures lock/refusal semantics and sibling routing, and the routing block explains the critical approval workflow. Minor redundancy exists between 'Approval-tier' and the bracketed outbound-tier note, but the redundancy reinforces a dangerous call instead of adding noise.

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 destructive, approval-gated live-theme mutation with no output schema, the description covers when to invoke it, when not to, what it refuses to do, how approval works, and which sibling tools handle adjacent cases. Nothing essential is missing for an agent deciding whether and how to call it.

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 explains all five parameters. The description adds value by clarifying the role of expected_updated_at as a lock obtained from get_shopify_theme_asset and requiring theme_id to be the live theme. This exceeds the baseline 3 without duplicating schema text.

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 opens with a precise verb and resource: 'Overwrite one existing file (Liquid/CSS/JS/JSON) on the LIVE (MAIN) Shopify theme.' It also names what the tool will not do — create new live files or operate on unpublished themes — and distinguishes itself from publish_shopify_theme and upsert_shopify_theme_file. This leaves no ambiguity about what the tool is for.

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?

It explicitly states when to use the tool: 'Use when the operator approves a single-file live-theme fix.' It also gives alternatives and exclusions: unpublished themes use upsert_shopify_theme_file, and swapping the entire storefront uses publish_shopify_theme. Approval routing is spelled out with the approval-card behavior and the expected_updated_at lock requirement.

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