blur_background

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

Annotations already declare the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=false, openWorldHint=true), so the description is not carrying that burden. It does add meaningful semantics — the subject stays sharp, so background blur implies subject detection rather than a uniform blur — but it says nothing about what happens if no subject is found, whether the source file is modified, or that a new file is produced.

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?

One sentence, front-loaded with the goal effect ('keep the subject sharp'), zero filler. Nothing could be removed without losing meaning.

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 simple deterministic image transform with full schema coverage, complete annotations and an output schema, the description covers the essential what-and-how-it-looks. The only remaining gap is failure/edge behavior when subject detection does not apply.

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% and all three parameters (image_path, radius, output_path) have their own descriptions including ranges, defaults and format constraints. The description adds nothing about radius tuning or output naming, so 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 and effect: blur the background while keeping the subject sharp, which cleanly separates it from remove_background, color_background and gradient_background as an effect choice. It does not explicitly name or contrast a sibling, so a 4 rather than 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 parenthetical '(portrait-style bokeh)' implies the intended use case (subject-isolating portrait imagery) but there is no explicit when-to-use, when-not-to-use, or routing signal against the sibling background tools. Usage must be inferred from the effect description rather than stated.

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