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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds meaningful behavioral context beyond annotations: all filtering fields are nullable, null must be sent when a constraint is unstated, and placeholders are forbidden. It also clarifies the data scope as public rather than private or provider-guaranteed, which is useful for invocation.

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?

Three sentences with the primary usage guidance front-loaded)SkipHere. Every sentence earns its place: when to use, null-handling rule, and explicit exclusions. No filler or redundant restatement of the schema.

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 read-only filtering tool, the description explains scope, constraints, null semantics, and exclusions, which covers most invocation needs. There is no output schema and the description does not describe the exact return shape, but the phrase 'model capabilities' plus filter context makes the expected result reasonably inferable, leaving only a minor completeness gap.

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 baseline is 3; each parameter already has a clear description like 'or null unless the user constrained it.' The description's global instruction that every filtering field is nullable reinforces the schema but does not add substantial new parameter-level meaning beyond what is already present.

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 states a specific action (list) applied to a clearly bounded resource: 'current public MaxVideoAI image or video model capabilities,' including audio and reference-image support. It further distinguishes itself by explicitly excluding generation, exact pricing, private models, and provider guarantees, so an agent can tell it apart from siblings like get_model_details or prepare_generation.

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?

It opens with 'Use this when the user needs current public...' and closes with 'Do not use it for generation, exact pricing, private models, or provider guarantees,' giving practical selection guidance. It does not name specific sibling tools as alternatives, but the exclusions effectively route agents away from clearly different operations.

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