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

Annotations already declare readOnlyHint=true, destructiveHint=false, and a closed world, so the safety profile is covered. The description adds real value by describing the returned structure (criteria, judge focus, scale), which matters because there is no output schema, though it says nothing about pagination or size limits.

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?

Two tight sentences with no filler; contents are front-loaded, followed by usage conditions and the id source. Every clause 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?

For a read-only fetch with no output schema, the description covers return shape, usage context, and prerequisite sourcing of the required id. An agent has everything needed to select and 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 coverage is 100%, so the baseline is 3, but the description goes further by telling the agent where to source the required rubricId (rubrics_list or an eval's rubricId) and notes the read-before-update relationship. That provenance guidance is genuine added meaning beyond the schema.

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 ('One rubric with its criteria') and enumerates the payload contents (criterion name, what the judge looks for, score scale). It is cleanly distinguishable from caliper_rubrics_list and caliper_rubrics_update in the sibling set.

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?

Explicitly gives two when-to-use conditions ('to explain a score' and 'before caliper_rubrics_update') and names the alternatives for obtaining the required id ('caliper_rubrics_list or an eval's rubricId'). Nothing is left to inference.

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