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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds only that results come with ids and the GET /v1/lists endpoint; it says nothing about pagination behavior despite default limit=50, which is the one behavioral trait an agent could trip over.

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?

Three short, front-loaded sentences with no filler. It is slightly terse: the word 'All' sits awkwardly beside a paginated endpoint that defaults to 50 items, so a qualifier would have earned 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?

No output schema exists, and the description does indicate the key return element (list ids), plus the endpoint for orientation. For a two-parameter, zero-required list tool with full annotation coverage, this is nearly sufficient; only pagination expectations are left unaddressed.

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 description coverage is 100% – both limit and offset are fully documented, including the useful 'Pass the previous reply's next_offset' hint. The description adds no parameter meaning beyond the schema, so baseline 3 is correct.

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 ('All contact lists of the account, with their ids') and the underlying endpoint, which is enough to distinguish it from siblings like sarbacane_list_campaigns or sarbacane_list_contacts. It stops short of explicitly contrasting with those siblings, so it lands at 4 rather than 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?

'Use the ids for contacts, fields and campaigns' implies the follow-on workflow (fetch lists first, then drill into fields/contacts/campaigns), which is genuine usage guidance. But it never states when NOT to use this tool or names a specific alternative sibling, leaving routing to inference.

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