request_backfill

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

With no annotations provided, the description carries the full burden. It explicitly discloses the asynchronous nature of the job and explains the default range behavior when from_date/to_date are omitted. However, it does not mention potential side effects like duplicate jobs or rate limits, though the async disclosure is substantive.

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 description is two sentences with no filler. The first sentence front-loads the purpose and async behavior, while the second sentence efficiently captures the parameter semantics in a compact, readable way.

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?

The description covers the core behavior and parameter logic adequately, and an output schema exists so return values are covered. However, for an asynchronous tool, it fails to mention the sibling backfill_status for checking job progress, and it omits any constraints or limits on the backfill request. This leaves a meaningful gap in the overall workflow context.

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. It clearly explains that from_date/to_date bound the range and that omitting both walks back from the newest message until max_messages. This adds meaningful inter-parameter semantics beyond the bare property names, though chat_id is only implied and date formats are not specified.

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 states a specific verb and resource: "Ask the service to download older history for a chat from Telegram (async job)." This clearly identifies the tool's function and distinguishes it from siblings like get_messages or search_messages by emphasizing it is an asynchronous download request.

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 description implies when to use the tool (when older history is needed) but does not explicitly name alternatives or exclusions. It also does not mention that backfill_status should be used to monitor the progress of this asynchronous job, leaving the agent to infer the workflow.

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