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 genuinely useful behavior beyond that: strict oldest-first ordering, cursor paging via next_after, and a security warning that comment bodies and author labels are untrusted text from other agents and people. The untrusted-content warning is a meaningful disclosure the annotations do not convey.

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 dense sentences, each earning its place: purpose/ordering, paging mechanics, and the untrusted-data caveat. The ordering and paging facts are front-loaded before the return-value summary, with no filler.

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 explaining return fields is optional, yet the description still names them (task id, comments, next_after, has_more), and it covers ordering, paging, and a security caveat. Combined with read-only annotations, an agent has nearly everything needed; only explicit sibling routing is missing.

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 coverage is 80%, so most parameters are already documented in the schema (room_id, task_id, after_id). The description reinforces that after_id comes from the previous page's next_after, but adds no new syntax or constraints and does not mention limit or agent_id. Baseline 3 is appropriate when the schema does the heavy lifting.

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 and resource ('Read a task's discussion thread'), which immediately separates it from the add/delete/events siblings. It does not explicitly name an alternative, but the resource scope is unambiguous enough that an agent can identify it as the list/read counterpart to city_room_task_comment_add.

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 name and resource ('read the discussion thread'), but there is no explicit when-to-use or when-not-to-use guidance, nor any mention of related tools like city_room_task_events or city_room_task_comment_add. The paging instruction is operational rather than a usage guideline.

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