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

Annotations already declare readOnlyHint=false, destructiveHint=true, idempotentHint=true, and openWorldHint=true, so the safety profile is covered. The description adds real context beyond them: writes to Shopify 'immediately' (live side effect, no staging) and that an empty string clears existing alt text, which is exactly the destructive behavior the hint warns about.

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 operation and scope in the first clause, then immediacy, then quality guidance. Three sentences, each carrying distinct information with no restatement of the title.

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?

With an output schema present and annotations covering the safety profile, the description only needs to add the non-obvious operational facts, which it does: single-image scope, immediate write, and clearing semantics. Nothing needed to invoke 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 coverage is 100%, so baseline is 3, but the description adds meaning the schema does not: the schema allows maxLength 512 and states 125 characters as an upper bound for good alt text, while imageId is tied back to get_resource. That constrains usage beyond the raw type declaration.

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 ('Set the alt text for ONE image') and pins the scope to a single image by id, which cleanly separates it from the sibling update_image_alt_bulk. An agent can pick this over the bulk variant without inspecting either 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?

Gives clear when-to-use context: operating on one image by imageId sourced from get_resource/get_image, and notes that an empty string clears the value. It implies but never explicitly names update_image_alt_bulk as the alternative for multi-image work, so there is no stated exclusion.

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