Convert or resize an image

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

Annotations already declare readOnlyHint=false, openWorldHint=true and destructiveHint=false, so the safety profile is largely covered. The description nonetheless adds real behavioral context beyond the annotations: the output link expires after 24 hours, the response includes source and output details, and the image itself is only returned when small enough. It omits any statement about auth or rate limits, keeping it short of a 5.

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 tightly packed clauses with zero filler: the conversion/transformation capabilities come first, followed by the return-value contract. Nothing is redundant with the schema and the most decision-relevant information is front-loaded.

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 12-parameter tool with no output schema, the description covers both the operation surface and the return contract (24-hour link, source/output details, conditional image body). Nothing an agent needs in order to invoke it correctly is missing.

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 100%, so the schema already documents every parameter including enum meanings, ranges and defaults. The description only restates the operations in prose without adding syntax, format or interaction detail beyond what the schema provides. Baseline 3 applies.

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 specific verb (converts) and resource (an image at a public URL), enumerates the supported output formats and the transformation operations, so an agent can distinguish it from inspect_image and generate_social_image without opening the schema.

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 requirement of a public source URL implicitly scopes usage, but the description never states when to prefer this tool over siblings like inspect_image, generate_social_image or capture_screenshot, and gives no exclusions or prerequisites. Usage is inferable rather than stated.

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