Get thread

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

With no annotations, the description carries the full burden and does meaningful work: page ordering, attachment metadata present but bytes absent, and tapbacks omitted unless include_reactions is true. It omits operational traits such as pagination termination and error behavior when the chat cannot be resolved, so it is strong but not exhaustive.

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?

The opening sentence is front-loaded and efficient, but the second sentence ('No MESSAGES_SCOPE and MESSAGES_ALLOW_UNSCOPED is unset; list/search/thread/send/watch return SCOPE') is cryptic jargon-heavy shorthand that resists parsing and interrupts the flow between purpose and identity resolution.

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?

For a 7-parameter, all-optional, no-output-schema, no-annotation tool, the description covers identity resolution, pagination, date filtering, and reaction handling adequately. It leaves a gap around what happens on unresolved chats or empty results, but nothing essential for correct invocation 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 100%, so the baseline is 3, and the description earns credit by clarifying that 'before' accepts either a message_id or an ISO timestamp and that from_date/to_date filter on the converted Apple date. It also spells out that guid can arrive via the handle field or chat_id, adding meaning beyond the schema labels.

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 and resource ('Return messages for one chat') plus an ordering guarantee ('oldest-first within the page'), which is enough to distinguish it from messages_list_chats. However, it never explicitly contrasts itself with messages_search, the sibling most likely to be confused with a message-retrieval tool.

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 conditional guidance for identity resolution (chat_id, guid, or participant handle) and the single-chat fallback when nothing is supplied, which is genuinely useful. It does not say when to prefer this tool over messages_search or messages_list_chats, so alternative selection is left implicit.

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