Image Read

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

The description frames a purely passive read ('Return ... as inspectable PNG', 'this server invokes no model or upload'), yet readOnlyHint=false declares the operation is not read-only. An agent that trusts the description will treat this as a safe read while the annotation says state may change, which is the contradiction pattern. The genuinely useful disclosures (bounded output, one-still limitation for animated inputs, no model/upload) are undermined by this mismatch.

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?

Three tight sentences with the core purpose front-loaded and no filler; the animated-input caveat and the model/upload note are compact. It is slightly abstract in phrasing but earns its length.

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?

An output schema exists so return values need not be explained, and the description covers purpose, the animated-input limitation, and the no-model/no-upload behavior. Only the missing sibling-routing guidance and the annotation mismatch leave a gap.

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 file_path, max_pixels, and include_image are already fully documented. The description only echoes the bounding concept via 'bounded local still image' and adds nothing about max_pixels semantics or the include_image toggle, so the schema carries the load.

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 concrete verb and resource ('Return a bounded local still image') plus the output form (inspectable PNG and exact source metadata), so the agent knows what it gets back. It does not explicitly differentiate itself from close siblings such as image_crop, image_ocr, or media_info, which keeps it below 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 implies usage by describing behavior on animated inputs, but never states when to reach for this tool versus image_crop, image_edit, video_frame, or media_info, and gives no when-not conditions. Context is implied rather than prescribed.

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