Get a gallery

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

Annotations already declare a benign read-only operation ('readOnlyHint: true'), so the description does not need to re-state that. It adds non-obvious context: the tool 'does not download image files' and AI galleries are returned with is_ai=true. These traits are genuinely helpful and go beyond the annotations. There is no contradiction with the annotations.

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 three or four short sentences and each one carries meaningful information: the result, the path interpretation, and the open_url caveat. No redundant phrasings or padding. It is slightly longer than the leanest versions, but there is no wasted text.

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 4-parameter tool with a fully documented schema, 100% parameter coverage, an output schema, and read-only/open-world annotations, an AI agent has enough to call it. The description ties the tool to its output domains--title, tags, image-url window--and flags the non-obvious download and AI behavior, so nothing required for a correct call is left unexplained.

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?

The input schema has 100% coverage and already describes every parameter, including path types, limit/offset bounds and defaults, and the source enum. The description reiterates the path semantics, so it adds little over the schema. Since schema coverage is high, 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?

States a specific verb and resource: 'Fetch title, tags, and a window of image URLs for one gallery.' It explicitly names what the tool returns and limits itself to a single gallery, which lets an agent distinguish it from list/browse/search-style tools. The reference to the path and the built-in exclusion of downloads further sharpen its purpose.

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 gives explicit routing: 'If the user gave a full URL and you do not know the source, call open_url instead.' It also clarifies the path comes from listing/search hits, implying the tool is used after a browsing/search step, and notes it works with a relative path or full post URL. It does not systematically contrast against every sibling like browse or search, but the key exclusion (open_url) is explicit.

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