set_keyframe_interpolation

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

Annotations declare destructiveHint=true and idempotentHint=true, so the safety profile is partly covered. The description adds real context beyond them: 'asset-level, headless' distinguishes it from editor/PIE variants, and embedding the return shape (key_found, saved, save_error) discloses that the edit is persisted and can silently miss an existing key. It does not spell out what existing tangent/interp values get overwritten, which is the main destructive behavior an agent would want confirmed.

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?

The purpose sentence is front-loaded and wastes nothing, and the parenthetical scoping qualifier earns its place. The trailing Returns block enumerates eleven fields, which is mildly verbose for prose but justified because no output schema is present to carry that 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?

Given no output schema exists, the description compensates by inlining the full return shape, and it covers purpose, scope and precondition. It stops short of explaining failure handling when the key is absent (only key_found/save_error fields hint at it) or whether the target sequence must be loaded first.

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 every parameter is already documented in the schema, and the description only restates the three things being set (interp mode, tangent mode, tangents). Per the baseline rule for high coverage, a 3 is appropriate with no added syntax or format detail.

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+resource: set interpolation mode, tangent mode and tangents on an existing keyframe, scoped precisely to a 'master float track's channel (asset-level, headless)'. That scope wording implicitly separates it from binding-channel and runtime interp siblings, but it never names an alternative tool, so an agent must infer the boundary rather than being told.

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 when-to-use, when-not-to-use, or alternative-tool guidance. The only implied precondition is 'an existing keyframe', which hints the key must already exist but is not stated as a rule. In a toolset with set_binding_channel_keyframe_interp, set_transform_track_interp_mode and set_anim_curve_interp_mode nearby, this omission leaves selection ambiguous.

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