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

With no annotations, the description carries the burden of disclosure. It mentions 'public residual fingerprint surface', which implies a safe, read-only operation, but does not explicitly state that it has no side effects, nor does it disclose any rate limits or data-access restrictions. This is partial transparency.

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 two sentences with no filler. The action and scope are front-loaded in the first sentence ('Query residual state of a single CDDG plane (0..359)'), and the second sentence adds a concise definition of the domain. Every word earns its place.

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?

There is no output schema, so the description should explain what the returned 'residual state' looks like (e.g., type, format, units) but does not. It also omits error conditions or edge cases. It provides enough for a simple query but lacks important return-value context.

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?

The schema already fully describes the 'plane' parameter (index 0..359), so the baseline is 3. The description adds conceptual meaning beyond the schema by defining CDDG as 'Continuous Dark-Degree Geometry — public residual fingerprint surface', which enriches an agent's understanding of what the plane represents.

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 states a specific verb ('Query') and a specific resource ('single CDDG plane') with an explicit index range (0..359). It clearly identifies what the tool does and distinguishes it from aggregate tools like cddg_residual_summary by emphasizing 'single', though it does not name any sibling explicitly.

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?

No guidance is given on when to use this tool versus alternatives such as cddg_residual_summary or cddg_residual_energy. It only explains what it does without any context for selection, prerequisites, or exclusions.

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