tg_download

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

Annotations already cover idempotentHint=true, rereadOnly=false, destructive=false, and openWorld=true. The description adds one useful behavioral detail (the default destination directory), but does not disclose what happens if the message has no media, whether it overwrites existing files, or whether it returns a path. With annotations carrying the safety profile, this modest addition merits a 3.

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 one short sentence plus a helpful default-location detail. It is front-loaded with the primary action and leaves out filler. It loses one point because it could have used the remaining space to clarify parameters or mention the many-sibling.

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 download tool with no output schema and 0% parameter coverage, the description leaves too much unspecified: how to identify the chat, the destination path semantics, and the expected result. Annotations clarify safety and idempotency but not operational details like file naming, overwrite behavior, or error cases, so the description is not complete for correct invocation.

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%, and the description adds no parameter-specific meaning: it does not clarify what 'chat' expects (ID vs username vs entity), the format of 'message_id', or what 'dest' accepts (relative vs absolute path). The only hint is that the default destination is data/downloads. With zero schema coverage, the description fails to compensate for the 3 undocumented parameters.

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 ('Download') and resource ('the media attached to one message'), and clarifies scope by saying 'one message' — distinguishing it from tg_download_many. It does not name the sibling explicitly, but 'one message' vs the many-sibling makes the distinction clear enough.

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 the tool is for downloading media from a single message and the default destination is project's data/downloads. It gives context but no explicit when-to-use guidance or alternatives; the sibling tg_download_many is implied but never mentioned. A 3 is appropriate because the context is present but exclusions are left to inference.

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