add_blendspace_sample

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

Annotations declare readOnly=false, destructive=false, idempotent=false, but the description adds a genuine behavioral detail beyond them: a failed save yields success=false with saved=false and save_error, which lets the agent detect partial failure. It still does not say that repeated calls append duplicate samples (relevant given idempotentHint=false) or what happens to the blend position if omitted.

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 blocks, with the core action front-loaded before the failure/return details. The explicit return field list is justified because no output schema exists, though the inline object literal is slightly dense.

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 3-parameter mutation with full schema coverage and no output schema, the definition covers action, failure signaling, and the return shape, which is the important missing structural piece. Only the appending/duplicate behavior and any asset-existence prerequisite are left unstated.

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 blend_value (1D number vs up to 3-element array, default 0), animation_path, and blendspace_path are already documented in the schema. The description's 'animation + blend position' wording adds no syntax or format detail beyond what the schema provides, so the baseline 3 applies.

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?

States a specific verb and resource ('Add a blend sample ... to a BlendSpace') and clarifies in parentheses that a sample is an animation plus a blend position, so an agent immediately knows what is created. It does not name the sibling operations (edit_blendspace_sample, remove_blendspace_sample, get_blendspace_samples) it must be distinguished from, so it stops 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?

Usage is only implied by the name: the agent can infer 'use this to add a sample' but there is no explicit when-to-use, no prerequisites (e.g. blendspace must exist), and no routing against edit_blendspace_sample or add_blendspace_sample duplicates. Adequate but with a clear gap.

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