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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is fully covered. The description adds one genuine piece of behavioral context — that results include credit cost — but says nothing about the shape of each entry, whether the list is paginated or static, or how models are identified.

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?

A single well-formed sentence that front-loads the verb and resource and appends the most decision-relevant extra detail (credit cost). No filler, no restatement of the title beyond what is needed.

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 zero-parameter, read-only listing tool with full annotation coverage, this is close to sufficient. The only shortfall is that there is no output schema, so the description is the sole source of information about what each returned entry contains, and it gestures at cost without describing identifiers or fields.

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 tool takes no parameters and the schema is empty, so there is nothing for the description to clarify; baseline 4 applies. The description correctly avoids inventing filtering options that the schema does not support.

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?

"List the image and video models available through Kreavo" is a specific verb plus resource, and it adds the distinguishing detail that each entry carries its cost in credits. It doesn't explicitly name a sibling tool, but the discovery nature of the call is unambiguous against generate_image, image_edit, and the status-check tools.

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 only implied: an agent can infer it should call this to see which models and prices exist, presumably before generating. There is no explicit statement such as "call this first to obtain a model identifier for kreavo_generate_image", and no exclusions or alternatives are named.

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