Labels

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so the safety profile is fully covered without description help. The description adds little behavioral context beyond the field list, which the output schema already provides. With annotations carrying the burden, a baseline 3 is appropriate.

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 short sentences, zero waste, with the identity of the resource front-loaded and the actionable cross-reference second. 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 zero-param list tool with a full output schema and complete annotation coverage, the description provides what an agent needs: what it returns and how to use it. It could be marginally stronger by noting ordering or scope, but nothing essential is missing.

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 tool takes zero parameters, so per the rubric the baseline is 4. There is nothing for the description to disambiguate, and it correctly focuses on the return payload instead.

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 the resource precisely ('account's triage labels') and enumerates the returned fields (id, name, color), which distinguishes it from unrelated siblings like list_rules or list_machines. The 'list' verb is only implied, and it doesn't explicitly contrast with the other list_* tools, so it falls short of a 5.

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 how the output is consumed: 'Use an id in search_events' labels filter.' This gives clear downstream context and connects to a named sibling. It does not state when to prefer this over alternatives or any prerequisites, so no exclusions exist.

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