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

Annotations already declare readOnly/idempotent/non-destructive, but the description adds hard behavioral constraints they cannot express: identical reads refused within 60s, a 300-reads-per-account-per-day inbox cap, and the risk of LinkedIn account restriction from polling.

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 the action, then the anti-pattern warning, then the workflow placement. Slightly redundant in citing three equivalent API identifiers (Voyager path, Kanbox name, REST route), which costs a little density.

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?

An output schema exists so return values need no explanation, params are fully covered by the schema, and the description supplies the safety, rate-limit, and workflow context an agent needs before invoking it.

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% and all three parameters are documented there, including created_before's millisecond Unix-timestamp semantics and the origin of conversation_linkedin_id. The description only restates provenance and the paging intent, adding no syntax or format detail beyond the schema.

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 messages in a LinkedIn conversation') and pins it to the exact Voyager endpoint and the equivalent REST route, so it is unmistakable against siblings like list_conversations or salesnav_list_thread_messages.

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 says when NOT to use it ('Do not call this in a loop to wait for replies') and names the alternative ('Subscribe a webhook to message.received instead'), plus the prerequisite ordering ('Use after list_conversations to read a thread before replying').

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