Add Pulley

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

Annotations already indicate readOnlyHint=false and destructiveHint=false. The description adds useful behavioral detail beyond those annotations: the +Z axis orientation, the z-span of the toothed belt face, the flange construction rule, the height-overrides-width behavior, and the exact return dictionary. It does not spell out the side effect on the active document, but the 'add' verb plus the non-read-only annotation make that clear.

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 long but every sentence carries necessary information: formulas, defaults, geometry orientation, and return values. It is front-loaded with the core purpose and then systematically covers each parameter in order, with no filler or repetition.

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 0% schema coverage and no output schema, the definition is nearly complete: it includes all parameter semantics, units, geometry behavior, and return fields. The only minor gap is that 'V pulley' is mentioned but no parameter or formula is provided for V-groove geometry, leaving that variant underspecified; the timing-belt path is fully covered.

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 fully document all 7 parameters, and it does. It explains teeth count minimum, belt_pitch units and pitch-diameter formula, width meaning, flange geometry, height override semantics, placement translation, and the name label. This far exceeds the minimum and gives the agent everything needed to call the tool correctly.

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 opens with a specific action and resource: 'Add a timing-belt (or V) pulley as a static solid.' It clearly identifies the tool's purpose and distinguishes it from sibling add_gear, add_sprocket, and add_bearing tools by focusing on pulley-specific concepts like belt_pitch, teeth, and flanged retainers.

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 context for when to use the tool: when a timing-belt or V pulley is needed as a static solid, including mating geometry through pitch_diameter. It does not explicitly name alternative tools or give when-not conditions, but the purpose is specific enough that an agent can select it correctly without opening other schemas.

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