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

Annotations only declare readOnlyHint=true, so the description carries the rest: it discloses cursor pagination, the returned field set (sender type, status, content), and the underlying endpoint. It does not explicitly state that results are read-only/ordered, but it adds solid behavioral context beyond the annotation.

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 tight sentences, front-loaded with the resource and channel scope, followed by selector guidance and pagination. No filler; only the trailing endpoint reference is arguably redundant.

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 compensates by naming the returned fields and pagination behavior, and it covers all selector paths. Nothing critical is missing for a read-only list tool, though result ordering and empty-result behavior go unstated.

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 the schema already documents limit, cursor, lead_uid, agency_uid, created_at and thread_uid. The description restates the selector parameters and cursor pagination but adds no format or semantics beyond what the schema provides, matching the baseline 3.

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 (read) and resource (guest messages) plus the channel scope and the three selectable scopes (lead/thread/agency). It is clear what the tool returns (sender type, status, content). It stops short of explicitly distinguishing itself from siblings like hostfully_list_threads or hostfully_get_lead.

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?

It tells the agent which identifier to supply ('Give lead_uid, thread_uid, or agency_uid (or the default)'), which is implied usage guidance, but it never says when to prefer this over hostfully_list_threads or when to reach for hostfully_get_lead. No exclusions or prerequisites are given.

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