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

Annotations already declare readOnly, idempotent, non-destructive, closed-world reads, so the safety profile is covered. The description adds genuine behavioral context beyond them: the one-session-per-person-per-run model and, notably, that attribution exposes only post_id/comment_id/matched_keyword and never user-typed content — a data-availability constraint an agent would otherwise get wrong. It does not describe pagination behavior despite the cursor parameter.

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 sentences with no filler; the core purpose is front-loaded and each following sentence adds a distinct fact. Nothing is redundant with the title or annotations.

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?

With no output schema, the description must carry return-value semantics, and it only partially does: attribution fields are explained but the rest of a session's shape (status, channel, timestamps) and the pagination contract (next_cursor) are unstated. For a seven-parameter list tool with full annotation coverage this is adequate but incomplete.

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%, so all seven parameters (limit, status, channel, flow_id, contact_id, updated_since, starting_after) are already documented, including enums and the 404 behavior for unknown contact_id. The description adds no per-parameter meaning, so the baseline 3 applies.

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?

The description opens with a specific verb+resource ('List flow sessions') and adds the cardinality rule ('one session per person per run of a flow'), which an agent cannot infer from the name. It does not explicitly distinguish itself from siblings like get_flow_session or list_flow_session_events, but the list-vs-get distinction is largely self-evident from the name.

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?

Usage is implied by the listing semantics, but the description names no alternatives and gives no when-to-use/when-not guidance (e.g., use get_flow_session for a single session, list_flow_session_events for event history). The scope is clear enough that an agent can place it, but routing is left to inference.

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