raster_info

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

With no annotations, the description must carry the full burden of behavioral disclosure. It states that the tool returns metadata, which implies a read-only operation with no side effects. However, it does not mention any potential caveats, such as behavior if the path is invalid or whether the file must exist, which would provide additional transparency.

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, concise sentence that front-loads the purpose and includes a list of return fields. Every word contributes value; there is no fluff or 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?

The tool is simple, with one parameter and no output schema. The description adequately covers what is returned (key metadata fields) and distinguishes it from sibling operations. It does not describe error handling or specific units, but these are not essential for such a straightforward metadata-reading 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?

The schema has one parameter, 'path', with no description, and the tool description does not explain the meaning of the path parameter or what format it expects. With 0% schema description coverage and no compensation in the description, the parameter semantics are under-specified, even though 'path' is a common parameter.

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 uses a specific verb ('Return') and resource ('image metadata') and enumerates the exact fields returned (dimensions, format, mode, DPI, file size). This distinguishes it clearly from sibling tools like raster_convert or raster_resize, which perform transformations rather than just reading information.

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: use this tool to get metadata rather than to modify the image. However, it does not explicitly state when to use this tool or provide exclusions/alternatives. The context is fairly clear from the sibling tool names, but there is no direct guidance in the description itself.

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