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

Goes well beyond the annotations to disclose that the agent is rebuilt for the change to take effect, that re-attaching an already-attached skill reports no change without a rebuild, and that a name collision is refused with nothing changed. These idempotency/conflict/rebuild behaviors are exactly the context annotations cannot convey, and they are consistent with idempotentHint=true and destructiveHint=false.

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-loads the core action, then layers the skill-format, rebuild, idempotency and error behavior in dense, information-bearing clauses. Slightly long, but each sentence carries distinct behavioral value with no filler.

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 mutation tool with no output schema, the description covers the essential unknowns: the trigger (rebuild), idempotent no-op outcome, name-conflict failure mode, scope restriction and auth prerequisite. An agent has everything needed to call it correctly and interpret results.

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 coverage is 100%, so every parameter (name, skill, org_name) is already documented, including the skill reference syntax and the org_name default. The description largely restates the schema's skill format rather than adding new per-parameter meaning, so the baseline 3 is appropriate.

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?

Opens with a specific verb+resource+effect: 'Attach a skill to an agent so the agent can use it.' This distinguishes it cleanly from siblings like detach_skill, get_skill, list_skills and publish_skill without the agent needing to open any schema.

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?

Explicitly states the skill reference forms (catalog:<name>, org:<name>, bare name, @v<N> pin) and the precondition that an org skill must already exist, naming publish_skill as the way to create one. It also scopes usage ('Skills attach to agents only') and flags the account requirement, leaving no ambiguity about when this tool applies.

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