Drawing: Topology Check

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

Annotations declare readOnlyHint=true and the description is consistent ('Never modifies the drawing') while adding substantial context beyond the annotation: how connectivity is defined (touching another line, a tank outline curve, or a block reference box), that arcs/bulged segments are measured as true arcs, that arcs are not tested for crossings, and the full set of refusal conditions.

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 the core purpose, then connectivity semantics, then refusals. Dense but every paragraph carries distinct information; the middle paragraph could be tightened slightly but nothing is wasted.

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?

An output schema exists so return values need not be described, and the description covers the remaining burden: input semantics, connectivity rules, refusal preconditions, and the read-only guarantee. An agent has everything needed to call it correctly.

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 coverage is 100%, so the baseline is 3, but the description adds meaning beyond the schema: the gap-must-exceed-tol refusal constraint, that a layers entry must actually be a layer of the drawing, and that the default layers ship with their classification as evidence. These are semantic relations not derivable from the schema alone.

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?

Names a specific verb and resource ('Topology of a line network') and enumerates exactly what it detects: dangling ends, near misses, interior crossings. This clearly separates it from siblings like validation_check or drawing_diff without needing to open any schema.

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 gives useful preconditions (what gets refused: bad path, invalid layers, no network layer, non-positive tol/gap, gap <= tol) and states it never modifies the drawing, but it never says when to use this versus the sibling validation_check or drawing_understand. Usage is implied by the tool name rather than stated explicitly.

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