physics_set_material

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

With no annotations, the description carries the full burden. It does disclose one useful non-obvious trait: the tool attempts to add the material from the built-in library if it is not already in the model. However, it does not say whether existing material assignments are overwritten, what happens if the material name is not found, what permissions/auth are needed, or any failure behavior.

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?

Front-loaded with a one-line purpose followed by the library-fallback behavior, then structured Args/Returns. Docstring framing ('Args:', 'Returns:') is mildly verbose but every parameter line earns its place and there is no filler.

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 mutation tool with no annotations and no output schema, the description covers the action, auto-fetch behavior, all four parameters, and a terse return note. It still omits failure modes, overwrite semantics, and any preconditions, so it is adequate but not complete.

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 compensate and largely does: it explains material_name with concrete examples ('Silicon', 'Steel AISI 4340', 'Copper'), and clarifies that domain_selection defaults to all domains for the physics and model_name defaults to the current model. The physics_name parameter is only restated, but overall this adds meaning well beyond the bare schema titles.

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 ('Assign a material to physics domains') plus a distinctive behavioral note that the material is pulled from COMSOL's built-in library when absent. It is clear what the tool does, though it does not name any sibling to differentiate from (no sibling handles materials, so little differentiation is needed).

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?

No statement of when to use this tool versus alternatives, no prerequisites (e.g. physics must already exist, model must be loaded/open), and no exclusions. Only implied usage is conveyed through the Args defaults. An agent gets no routing guidance.

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