image-detect

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

With no annotations provided, the description carries the full burden. It discloses pricing ($0.050/call), no API key requirement, and the detection method (magic bytes). It mentions return fields but does not cover error behavior or rate limits. This is good but could be more comprehensive.

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 long, no fluff. It front-loads the core purpose and then lists return values in a structured manner. Every sentence adds value.

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 tool has one parameter and no output schema, the description compensates by listing return fields and pricing. It is fairly complete for a simple inspection tool, though error handling or response size could be mentioned.

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 only parameter 'url' has a schema description stating it must be publicly accessible and supports HTTP/HTTPS. The tool description adds context about the URL needing to be publicly accessible, which adds value beyond the 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 the tool's function: detecting true image format via magic byte inspection. It specifies the behavior even when extensions or headers are misleading, and lists return fields. This is a specific verb-resource combination that distinguishes it from siblings.

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 explains when to use the tool (when file extension or Content-Type may be inaccurate) and implies it works with any publicly accessible image URL. It does not explicitly mention when not to use it or compare with alternatives, but the context is clear.

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