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

Annotations already declare readOnly/idempotent/non-destructive, so safety is covered; the description adds genuine behavioral context beyond that, disclosing a degenerate case (principal-axis mirror residual is null for isotropic noncoincident covariance) and an interpretation caveat about rounded fingerprints. These are non-obvious traits an agent could not get from the annotations.

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?

Three dense sentences with no filler, and the core capability is front-loaded in the first sentence. The degenerate-case and caveat sentences each earn their place, though the vocabulary is heavy enough to slow comprehension.

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 annotations carry the safety profile. However, with two parameters and zero schema coverage, the unexplained reference_distance_fraction plus absent usage guidance leaves the definition short of complete for an agent trying 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 description coverage is 0%, so the description must compensate and largely does not. The 3–256 point count is echoed, but 'reference_distance_fraction' is never mentioned or explained in the description, leaving its meaning and effect entirely undocumented.

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 names a specific resource (3–256 planar points) and enumerates exactly what is computed: distances, nearest-neighbour isolation, centroid spread, PCA collinearity and histogram. The verb is implicit rather than stated, but an agent can tell this characterizes a point set geometrically and it is clearly distinct from siblings like analyze_kinematics or audit_statistics.

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?

There is no when-to-use or when-not guidance and no named alternative. The only usage-adjacent content is the closing caveat that rounded fingerprints are 'descriptive, not proofs of equivalence or method benefit,' which hints at a limitation but does not tell the agent when to pick this tool over another.

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