Open a gallery URL

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds that it 'picks the source from the URL host,' which is useful behavioral context. However, it doesn't disclose what happens with invalid URLs, redirects, or how the limit/offset affect the returned gallery, though the output schema may cover some of this.

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 two sentences with no waste. The main action is front-loaded, and the usage condition is stated in the second sentence. Every word earns its place.

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 the tool has an output schema, annotations for safety, and 100% schema coverage, the description is nearly complete. It could mention error behavior (e.g., invalid URL) or that it returns image URLs, but the output schema likely covers return values. The only minor gap is handling of non-gallery URLs, but overall it's sufficient for an agent to invoke correctly.

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 documents all three parameters. The description adds the key semantic that the URL is a 'full post URL' and that the source is derived from the host, which complements the schema. But it doesn't add much beyond that, so baseline 3 is appropriate.

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 clearly states the tool opens a gallery from a full post URL, with a specific verb ('Open') and resource ('gallery'). It distinguishes itself from siblings by noting it picks the source from the URL host and is for when the user pastes a link, which differentiates it from browse/search/get_gallery.

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 says 'Use this when the user pastes a link,' providing a clear usage condition. It also implies the alternative (browse/search) for other cases, and the sibling list reinforces the context. This is explicit enough for an agent to select it correctly.

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