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

Annotations already establish readOnly/openWorld=false/destructive=false, so the safety profile is covered. The description adds real behavioral context beyond them: 'DB-backed, instant, unpaged' tells the agent there is no pagination loop or eventual-consistency wait to handle, and the field list pre-empts output discovery.

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, scope, and return shape, then routing. Every clause carries information, though the long compound sentences in the second half are dense and slightly harder to scan than a bulleted alternative listing would be.

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?

No output schema exists, and the description substitutes by enumerating return fields with meaning (campaignCount = campaigns you can see, shared = install-wide). Together with the routing table for related ICP tools, an agent has everything needed to call and use 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?

The tool takes zero parameters, so the baseline is 4. The description instead documents returned identifiers (id, name, description, campaignCount, shared, editable), which is the more useful semantic information for a parameterless list call.

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+resource ('List the ICP labels') and immediately scopes it: labels attachable to campaigns, returned newest first. It explicitly distinguishes itself from li_list_strategies and li_list_campaigns, so an agent can route without opening another schema.

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?

Goes well beyond context: it explains what an ICP *is* (a label for comparing audiences) and names the exact downstream tools/fields where the value is consumed (icpId/icpName to li_create_campaign / li_ingest_prospects, li_edit_campaign to change, li_outreach_analytics(groupBy="icp") to compare, li_create_icp to create). This is explicit when-and-how guidance with alternatives named.

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