modify_arc

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

With no annotations, the description carries the full burden. It discloses that the tool modifies arcs, describes partial update behavior, and lists possible arc types. It does not cover destructive implications or permissions, but it is fairly transparent for a mutation tool.

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 concise and well-structured: purpose first, then usage note, then parameter list. Every sentence adds value without redundancy.

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 the tool's complexity (3 parameters with partial updates) and the presence of an output schema (not shown but indicated), the description is complete. It covers what the tool does, how to use it, and parameter details, leaving no obvious gaps.

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 compensates well. It explains each parameter: arc_id is required for identification, weight and arc_type are optional with explicit examples ('normal', 'inhibitor', 'read'). It adds meaning beyond the schema, such as the partial update behavior.

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 clearly states 'Modify an existing arc in the Petri net,' using a specific verb and resource. It distinguishes itself from siblings like 'add_arc' and 'remove_arc'.

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 provides clear usage guidance: 'Only provided fields are updated — omitted fields stay unchanged. Use list_elements to discover arc IDs first.' It explains partial update behavior and suggests a prerequisite for finding arc IDs, though it doesn't explicitly mention when not to use this tool.

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