spine_add_animation

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

With no annotations, the description carries the full burden. It does disclose a meaningful behavioral trait — the created animation is empty and must be filled via spine_set_keyframes — which is genuine value beyond the schema. However, it says nothing about permissions, duplicate-name handling, or whether the operation is idempotent, which matters for a mutation tool with zero annotation coverage.

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, front-loaded with the action and followed immediately by the next-step pointer. No filler or redundancy.

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?

An output schema exists, so return values need not be described. Still, for a mutation tool with no annotations and undocumented parameters, the description leaves out failure modes and project/name resolution, which an agent would need to call it reliably.

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 0%, so the description must compensate for both parameters, yet it never explains what "project" refers to (path, name, or id) or how "name" is interpreted. The only parameter-adjacent hint is the word "empty" implying keyframes aren't supplied at creation, which is thin compensation for a total coverage gap.

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 ("Create an empty animation") and explicitly distinguishes the result from the keyframe tool by saying the animation starts empty. It is clearly different from siblings like spine_delete_animation or spine_duplicate_animation, though it doesn't address relationships to spine_create_project or spine_add_skin.

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 second sentence implies the intended workflow — call this, then use spine_set_keyframes to populate it. That is useful sequencing guidance, but there is no statement of when not to use it, what preconditions apply (does the project need to exist?), or what happens if the name is taken.

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