get_image

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

With no annotations, description fully carries burden. Discloses return format (inline bytes for Claude), graceful failure on missing/expired media, and implicit read-only nature. Could mention if any side effects occur, but download implies none.

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?

Two sentences, front-loaded with purpose and usage. Efficient but could be slightly more structured (e.g., separate usage and behavior).

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, but describes return format and error cases. Covers essential aspects for a simple image retrieval tool. Adequate for the complexity.

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 has 0% coverage (no descriptions), but description adds meaning: msgId and chatId come from get_recent_messages results. This compensates well for the lack of schema descriptions.

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 tool downloads a cached image and returns bytes inline for Claude to see, mentioning a specific use case (Opus vision) and distinguishing from siblings like get_recent_messages and save_image.

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?

Provides explicit context: pass msgId and chatId from get_recent_messages when hasMedia=true and type=imageMessage. Mentions failure conditions (missing keys, expiry). Lacks explicit 'when not to use', but context is sufficient.

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