Get statistics

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so the safety profile is covered. The description adds the instance-wide scope and hints at the content (asset counts), but says nothing about permission level (this endpoint is typically admin-gated) or cost/latency of a full-instance aggregation.

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 'Get statistics' line restates the name and title verbatim, and the operation/route footer is boilerplate rather than agent-facing guidance. Only one sentence carries real information, so the structure is compact but only partially front-loaded with substance.

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 no output schema, the description carries the burden of explaining what comes back, yet it only offers 'such as asset counts' as an example. An agent cannot anticipate the returned fields (storage usage, per-type counts, etc.), and no auth prerequisite is noted for an instance-wide endpoint.

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 tool takes zero parameters, so there is nothing for the description to disambiguate; baseline 4 applies. No parameter text is required or missing.

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 second sentence states a specific verb and resource (retrieve statistics) and scopes them to the 'entire Immich instance such as asset counts', which is meaningful because the sibling list contains many narrower statistics tools (album, asset, person, library, activity statistics). It does not explicitly name those siblings, so differentiation is implied by scope rather than stated.

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?

There is no when-to-use statement and no routing to alternatives, even though the sibling set offers five or more competing '*statistics' tools. The agent must infer from the phrase 'entire Immich instance' alone that this is the global, not per-entity, choice.

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