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

Annotations already declare readOnlyHint/idempotentHint true and destructiveHint false, so the safety profile is covered. The description adds genuinely new behavioral context beyond that: the call is free with no credits charged, and the response also includes the account balance — two facts the annotations cannot convey.

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 short sentences with zero filler; the core action is front-loaded and the cost-safety reassurance is appended where it matters most. Nothing could be removed without losing information.

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 no-required-parameter, no-output-schema pricing tool, the description covers what it returns (price and balance) and that it is free. Minor gap: it does not clarify whether the quoted price depends on the supplied image, which an agent might wonder about given image_url/image_base64 inputs.

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 the enum descriptions already spell out credit costs per output option and URL/base64 constraints, so the schema does the heavy lifting. The description adds no further parameter meaning such as whether image_url or image_base64 is preferred, or whether the quote varies by image size.

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 gives a specific verb and resource: it returns the credit price of converting an image to PPTX/SVG plus the account balance. That distinguishes it in spirit from the sibling convert_image (which performs the work) and get_conversion (which presumably retrieves a result), though it never names either sibling explicitly.

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?

Usage is implied rather than stated: an agent can infer this is a pre-flight price check because the description says it 'shows' a price and nothing is charged. It never says to call this before convert_image, nor does it state any condition where quoting is unnecessary or inappropriate.

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