Read a conversation's messages

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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description adds real context beyond that: required scopes, 'data sensitivity: full_content', the workspace-override behaviour against the environment default, and pagination/truncation semantics.

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 core purpose in the first sentence, followed by compact operational facts (endpoint, scopes, idempotency, workspace override). No sentence is filler, though the scope/sensitivity lines are somewhat boilerplate.

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-shape explanation is unnecessary, and the description still notes truncation/nextCursor behaviour. Combined with the scopes and workspace-override notes, an agent has enough to call it correctly; only the query-parameter semantics are thin.

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 60%, so the baseline is 3. The description adds useful meaning for workspaceId/workspaceSlug (they override the environment-configured default workspace), but says nothing about the 'before' or 'limit' query parameters, leaving part of the coverage gap unfilled.

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 ('page backward through older messages') and resource (a thread's messages), and immediately scopes it to threads longer than the window returned by the conversation read, which distinguishes it from sibling luca_conversations_get.

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?

Gives a clear condition for use ('threads longer than the window the conversation read returns'), which implicitly routes the agent away from luca_conversations_get. It does not explicitly name that sibling or spell out when not to use this tool, so it stops short of a 5.

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