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

Annotations already declare a non-readOnly, non-destructive, closed-world write, so the description usefully adds what annotations cannot: name-collision refusal, demo-workspace refusal, layout skills sourcing their body from a board, and the visibility/approval model (reference and layout stay private, public action skills need approval). These are genuine behavioral facts beyond the structured fields, though nothing is said about authorization or idempotency behavior (the latter is left entirely to the schema).

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?

Front-loaded with the core action and the 'no execution' caveat, then proceeds kind-by-kind in a logical order. Six sentences is on the longer side, but each one carries distinct constraints (inputs per kind, refusals, visibility/approval, duplicate check) rather than restating the name or annotations.

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 10-parameter mutation with an output schema (so return values need not be described), the definition covers the branching input requirements, refusal cases, privacy/approval model, and duplicate-avoidance workflow. The remaining gap is that workspace targeting behavior (workspace_id / workspace_scope / cross-workspace writes) is left to the schema rather than the description.

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?

With 70% schema coverage across 10 params, the description adds real decision logic not in the schema: which parameter combinations apply per skill_kind (name+body+skill_kind vs. name+skill_kind+source_board_id), and what visibility means in practice for each kind. It does not explain workspace_id, conversation_id, idempotency_key, or workspace_scope, but those are well documented in the schema itself.

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 verb and resource — 'Save one skill in this workspace' — and immediately adds the crucial scope qualifier 'without executing it', which separates it from any invocation/execution path. It then distinguishes the three skill kinds (reference, action, layout) and their distinct inputs, so an agent can tell it apart from well_update_skill, well_get_skill, and well_search_skill.

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 gives an explicit precondition routing rule — read existing skills via well_query_records on skills before creating a duplicate — plus two refusal conditions (name already in use, demo workspace). It stops short of naming the obvious sibling alternatives (well_update_skill for modifications, well_search_skill for lookup), so context is clear but exclusions are incomplete.

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