messages_get_media

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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, so the safety bar is low, yet the description still adds real behavior: the file is saved locally with its path returned, images are shown, and transport (gRPC in-band vs REST/socket provider storage) changes retrieval. It does not cover permissions or failure modes, so a 4 rather than 5.

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?

Front-loaded with the core action and return behavior in the first two sentences; the transport detail and endpoint/gRPC suffix are compact. Minor technical framing but no wasted 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?

No output schema exists, and the description does cover the return (path returned, images shown), which is good. However it leaves the three required identifiers entirely unexplained, which is a gap for a 3-param read tool.

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 all three parameters (channelId, chatId, messageId) are undocumented in both schema and description. With low coverage the description should compensate, but it says nothing about what these identifiers mean or how they relate.

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: fetching a message's media and describing it. This distinguishes it from send/create siblings like messages_send_media, though it does not explicitly name the closest alternatives such as messages_attachments or messages_get.

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 only implied by the purpose; there is no explicit when-to-use or when-not-to-use guidance, and no routing to siblings like messages_attachments or messages_get. An agent can infer the context but must guess relative to alternatives.

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