save_image

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

No annotations are provided, so the description carries the full burden. It discloses the saving action and enumerates failure codes (not_found, not_image, etc.), aiding understanding. However, it does not explicitly mention side effects like overwriting or atomicity.

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 a single, well-structured paragraph. It begins with the core purpose, then details input sources, naming convention, return format, and failure codes. Every sentence adds value, with no redundancy.

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 tool with 6 parameters and no output schema or annotations, the description covers essential aspects: purpose, input requirements, storage location, naming, and failure modes. It lacks explicit success response structure, but the resource_link return is implied. Overall, it is fairly complete.

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 67% (4 of 6 params described). The description adds meaning beyond schema by explaining the source of chatId/msgId (from get_recent_messages), default folder format, and naming convention. For parameters like timeoutMs and skipIfExists, it provides defaults not in schema.

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 'Save a single WhatsApp image to disk', specifying the action (save) and resource (WhatsApp image). It distinguishes from siblings like 'save_media' (general media) and 'save_voice' (voice messages) by being image-specific.

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 instructs to 'Pass the chatId + msgId from a get_recent_messages result', providing clear context on when to use the tool. It does not explicitly state when not to use it or list alternatives, but the usage context is clear.

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