Download Chat Hosted Content

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

Annotations already disclose readOnlyHint=true and destructiveHint=false, meaning it's a safe read operation. The description adds that it returns base64 encoded data with metadata, which is useful, but does not mention how downloads work when savePath is provided or whether it still returns data. No contradiction, but limited additional behavioral context.

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, front-loaded with the primary action and return format, then a usage hint. It is concise and free of fluff, though it could have been slightly more structured, so a 4.

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?

Given the descriptions of parameters, annotations, and lack of output schema, the description provides sufficient detail for an agent to use the tool correctly. It mentions the return type (base64) and usage context, but does not cover edge cases like what happens when no hostedContentId is provided or savePath behavior. Minor gaps but overall complete for a read-only download.

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 every parameter has a description. The tool description adds no extra meaning beyond the schema. Baseline 3 applies since schema does the heavy lifting and the description doesn't need to compensate.

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 clearly states the verb 'Download' and the resource 'hosted content (such as images) from a chat message', and mentions it returns base64 data and metadata. It differentiates from sibling download_message_hosted_content by specifying 'chat message', but does not explicitly contrast with that sibling, so not a 5.

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 states 'Use this to retrieve images or other inline content embedded in chat messages' which gives some usage context, but it does not explicitly say when not to use it or contrast with the sibling download_message_hosted_content. It implies usage for chat-related content but lacks exclusionary guidance.

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