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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds real behavioral context beyond that: the call is 'Free' (cost disclosure) and the return is exactly three ideas whose 'action' field is directly consumable by animate_mascot. It does not say whether repeated calls are deterministic or cached, but the cost and output-shape notes are substantive.

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 short sentences, front-loaded with the deliverable and the cost before the integration note. Every sentence carries information, though the fragment 'Free.' and 'built on what it already has' are slightly informal for a spec.

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?

With no output schema, the description does the work of describing the return (three ideas, each with a passable action) and the cost. It omits the per-idea field structure and whether ideas are deterministic across calls, which are minor for a read-only suggestion tool.

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 both parameters (still_id, project_id) are already documented in the schema. The phrase 'built on what it already has' loosely hints at the still_id default of the approved character, but adds no syntax or format detail. Baseline 3 is appropriate when the schema does the work.

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 resource and output: three animation ideas for the given mascot, tailored to existing assets. It implicitly distinguishes itself from siblings by noting its output feeds animate_mascot, so an agent can separate it from add_pose or get_animation. The verb ('suggest') is only implied rather than stated, which keeps it short of 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?

There is no explicit when-to-use or when-not-to-use statement, and no named alternative to prefer. The one workflow cue ('each idea's action can be passed straight to animate_mascot') implies this is a precursor to animating, but the agent must infer the condition that selects this tool.

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