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

Annotations supply no positive hints, so the description carries the behavioral burden. It clearly discloses the append-only membership behavior, the inability to adjust fixtures after results are seen, and the required permission. Core mutation semantics are transparent.

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 sentences, each earning its place: the first states the purpose, the second flags the critical immutability constraint and permission requirement. 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?

For a low-complexity create tool with a single parameter, the description covers purpose, permission, and the main behavioral risk. It could mention the return value, but that is not essential for calling the tool 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?

The schema documents the single required name parameter with length constraints, but schema_description_coverage is 0%. The description adds no further meaning for the parameter, though the parameter is simple and self-descriptive.

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 concrete action and resource: it creates an empty owned collection for comparison. The phrase 'to measure against' clarifies the domain role, distinguishing it from sibling comparison tools like create_comparison_artifact and create_comparison_verdict.

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 explicit when-to-use or alternative routing is given. It implies use when a new comparison set is needed, but it doesn't mention add_comparison_runs for populating the set or explain how it differs from create_comparison_artifact/create_comparison_verdict.

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