femm_mirror_selected

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

With no annotations, the description carries the full behavioral burden, and it does disclose the single most important trait: the original geometry is preserved ('the original stays'). However, it omits whether a prior selection is required, coordinate/units conventions, what happens on an empty selection, or how the optional 'entities' and 'session' arguments alter behavior for this mutating operation.

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?

A single tight sentence with the action front-loaded and the non-destructive caveat appended. No filler, no restatement of the tool name.

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 mutating geometry tool with no annotations and no output schema, the description covers the operation and its non-destructive nature but leaves the session/entities parameters and preconditions undocumented. Adequate as a minimum-viable definition, but an agent could still misinvoke it with respect to session scoping or explicit entity lists.

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 it does give real meaning to the four required parameters by identifying (x1,y1)-(x2,y2) as the endpoints of the mirror axis. It says nothing about the two optional parameters ('session', 'entities'), leaving a third of the 6-parameter surface unexplained.

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 ('mirror-copy') plus resource ('the selection') and the exact geometric locus of the operation (the line through (x1,y1)-(x2,y2)). The parenthetical '(the original stays)' distinguishes it from femm_move_selected and clarifies it is a duplication rather than a destructive transform.

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 when-to-use guidance, no stated prerequisites (e.g. that a selection must already exist), and no routing to alternatives such as femm_copy_selected or femm_move_selected. The agent must infer the usage context entirely from the verb.

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