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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so safety is covered. The description adds real value beyond them: the OAuth auth requirement and the fact that the returned URL is a 'resolved dashboard image URL' rather than a raw asset path. It doesn't discuss error behavior for unknown IDs, which keeps it below 5.

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?

Three short sentences with the core action front-loaded, followed by prerequisite routing and the auth note. Every sentence earns its place and nothing is redundant.

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, the description needn't explain return values, and annotations cover safety; the remaining essentials (scope, auth, ID discovery path) are all stated. The single omission is the semantics of referenceId, which is a modest gap for a three-required-parameter tool.

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 0%, so the description must carry the burden, and it only partially does. It clarifies that 'type' means listing vs. profile (matching the enum) and that imageId is an image identifier discoverable via list_images, but it never explains that referenceId is the ID of the owning listing or profile — the one parameter most likely to be misconsumed.

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 ('Get one owned listing or profile image by ID') plus the scope ('owned') and a notable output detail ('resolved dashboard image URL'). It is unambiguously distinguishable from siblings like list_images (which returns many) and get_listing (which returns the parent resource).

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?

Explicitly routes the agent to the prerequisites: it names three sibling tools (get_listing, get_profile, list_images) as the way to obtain image IDs first, and adds the OAuth requirement. The only small gap is that it doesn't spell out when not to use it, but the required-ID prerequisite covers the main failure mode.

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