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

Beyond the readOnlyHint/openWorldHint annotations, the description discloses the non-obvious default state filter (a silent scoping behavior an agent could otherwise miss) and the 'enrolledUnits null means the count could not be read, not zero' caveat, which prevents a real misinterpretation. It also flags the load_skill prerequisite, which is operationally important.

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 with purpose and return contents, then defaults, then sibling routing, then the skill prerequisite. Most sentences carry distinct information, though the return-field enumeration is somewhat dense and the trailing skill instruction could be positioned earlier for prominence.

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 carries the burden of explaining return values — and it does so field by field, including the null-count edge case. Combined with default-filter semantics and sibling routing, an agent has everything needed to call this 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 adds real meaning by explaining the default value set for 'state' and its filtering consequence. Minor gap: it lists states as scheduled/active/ended/terminated while the schema enum also includes 'pending', leaving one accepted value unexplained.

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 ('List A/B experiments') plus the scope ('current project and environment'), then enumerates the returned fields (id, name, state, unit type, schedule, groups, enrolled units). This makes it instantly distinguishable from sibling list_* tools and from get_experiment / get_experiment_results.

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 tells the agent that the default is active+scheduled experiments and that 'state' must be passed to see ended or terminated ones. It also routes to concrete alternatives by name: get_experiment for targeting/configuration and get_experiment_results for group performance, plus a required skill load first.

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