mark_read

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

With no annotations, the description carries the full burden. It does disclose a useful behavioral trait — only the newest entry in message_ids is used, so extra ids are redundant — and that `to` defaults to the single subscribed target. It does not say what happens on failure, whether marking is idempotent, or any auth/subscription prerequisites.

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?

Purpose is front-loaded in the first sentence, followed by a compact per-argument breakdown. Given 0% schema coverage the parameter notes earn their place rather than being redundant, though the 'Args:' formatting restates schema key names.

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 not be explained. As an unannotated mutation tool the description covers the essential call semantics but omits permissions, error conditions, and what 'read' state changes for the target chat, leaving a moderate gap for a tool that alters shared state.

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 0%, so the description must compensate, and it does: it explains message_ids is sourced from channel events and only the newest is honored, and that `to` is a chat alias omittable when there is one subscribed target. This adds real meaning beyond the bare schema types.

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 action (mark messages read / emit a 'Seen' receipt) with clear scope: 'up to the newest of these messages'. An agent can distinguish it from sibling mark_thread_unread and from read tools like get_messages. It stops short of explicitly naming an alternative, so it is clear but not sibling-differentiating.

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?

The word 'Optional' signals this is not required for normal message flow, and 'Omit for the sole subscribed target' guides the `to` parameter. However there is no explicit when-to-use/when-not-to-use framing or reference to alternatives such as mark_thread_unread, so usage is only implied.

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