femm_set_block_prop

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

With no annotations, the description carries the full load, and it does disclose that this is a mutation of an existing entity selected by proximity. However, it omits critical behavior: what happens if no block label is near (x, y), and whether omitted optional parameters (group, turns, magdir, circuit, mesh_size) are left untouched or reset to defaults.

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?

Two compact sentences with the operation front-loaded and the use case second; nothing is wasted or buried.

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 9-parameter mutation tool with no annotations, no output schema, and zero schema documentation, the description is too thin. It should at minimum describe the failure mode when no nearby label exists and which parameters are overwritten versus preserved.

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% across 9 parameters, so the description must compensate, and it largely does not. "Same arguments as femm_add_block_label" defers to another tool's schema for x, y, group, turns, magdir, circuit, session, and mesh_size, and only the vague notion of "materials or currents" hints at material/turns semantics.

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 ("Change the properties of the existing block label") plus a spatial targeting rule ("nearest (x, y)"). The word "existing" implicitly separates it from the sibling femm_add_block_label, which creates labels, so an agent can distinguish the two.

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?

"Use to swap materials or currents between solves" gives a concrete scenario for reaching for this tool over alternatives. It offers no explicit when-not conditions or prerequisites, but the intended workflow is clear.

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