hole

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

Annotations only declare the generic non-readonly/non-destructive profile; the description adds real behavior beyond that — no thread is modelled for tapped holes, metric sizes carry standard ISO 4762/ISO 10642 head dimensions, and the face is derived from the first center point. It stops short of saying what happens on failure (centers off-face) or the cut direction/start.

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 purpose sentence, then per-parameter lines in the order an agent would reason about them (centers, size/fit, depth, style). Slightly compressed prose in the last clause, but no sentence 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?

For an 11-parameter feature-creation tool with an output schema present, the description covers the decision-relevant inputs (size vs diameter, through vs depth, style variants) well. Minor gaps remain on the counterbore/countersink dimension parameters and error conditions, but nothing critical to a correct call is missing.

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 55% across 11 parameters, so description carries real burden and does: centers format and coordinate system, size as metric designation, fit semantics (ISO 273 clearance vs tapped drill diameter), depth_mm or through_all=True, and style with standard counterbore/countersink dimensions. The explicit counterbore_/countersink_diameter_mm and angle parameters are only gestured at via 'otherwise give them'.

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 plus the geometric constraint: 'Drills round holes into a planar face, perpendicular to it.' An agent knows exactly what geometry results. It does not, however, distinguish itself from siblings like cut_extrude or sketch_circle+cut, so a 4 rather than a 5.

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?

Usage is implied rather than stated: the note that all centers must lie on the SAME face, found via the first center, tells the agent when the tool is applicable. There is no explicit 'use this instead of cut_extrude' guidance or stated prerequisites such as an existing part/document.

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