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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false, and destructiveHint=false, so the safety profile is covered. The description's 'Read-only.' merely repeats that and adds no behavioral context beyond the annotations, such as rate limits, auth needs, or side effects. The metric list adds scope but not behavioral traits.

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 front-loaded with the purpose and a detailed list of returned metrics, making it skimmable. The trailing 'Read-only.' is redundant with annotations and does not earn its place, slightly reducing conciseness.

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 return values, and it does so thoroughly by enumerating all metric categories. Annotations cover safety, params are absent, and the description is complete for a zero-parameter stats 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?

The tool has zero parameters, so the schema provides no parameter semantics to document. The description appropriately omits parameter discussion; baseline 4 for zero-param tools is warranted.

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 ('Return') and resource ('graph-level metrics for the world model'), and enumerates the metric categories. It does not explicitly differentiate from siblings such as query_world_model or get_cognitive_health, so it falls short of a 5.

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 only states what metrics are returned; it gives no guidance on when to use this tool versus alternatives like query_world_model or get_cognitive_health. No when-to-use conditions, prerequisites, or exclusions are provided.

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