model_state

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

Annotations already declare readOnlyHint and idempotentHint, so the description's 'Read-only' is redundant. However, it goes beyond annotations by explaining the return contents (mesh status, phase flags, unassigned material features) and the crucial distinction between 'blocking' and 'unknown' – preventing a false sense of safety. No contradiction with 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 front-loaded with the primary purpose, then adds necessary detail in a compact, layered manner. Every sentence contributes: the 'blocking'/'unknown' explanation is essential for correct interpretation. No wasted words or redundancy beyond the harmless 'Read-only' repetition.

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 zero parameters, an output schema, and strong annotations, the description covers all necessary context: what it returns (mesh, phases, unassigned features), what 'blocking' means, and the critical 'unknown' caveat. An agent can safely invoke this tool and interpret results without further documentation.

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, and the schema has 100% coverage (vacuously). The description correctly focuses on behavior rather than parameter syntax, which is appropriate. Baseline for 0 params is 4, and nothing in the description detracts from that.

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 opens with a specific verb+resource: 'Report whether the model can be calculated, and what is stopping it.' This clearly distinguishes it from siblings like 'calculate' (which performs the calculation) and 'view_results' (which shows outcomes). The scope is unambiguous.

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 implies use as a pre-calculation check ('what is stopping it' before a calculate call) and provides clear context for when to invoke it. It does not name specific alternatives or explicitly say 'when not to use', but the intended context is evident from the tool's purpose.

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