enable_skill

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

Annotations (readOnlyHint=false, destructiveHint=false, idempotentHint=false) indicate this is a mutating, non-idempotent operation, but the description goes further by explicitly stating that it 'Persists a new binding', which implies state change and non-idempotency. It also reveals the routing behavior through route_capabilities and scope under the caller's user scope—valuable context not covered by annotations.

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 description is three sentences, front-loading the primary outcome, and each sentence serves a purpose: first states action and result, second describes the internal mechanics, third provides lifecycle guidance. No fluff or repetition.

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 and no annotations covering side effects, the description adequately covers the persistence and removal. It doesn't explicitly state what happens if the skill already exists (e.g., overwrite vs. duplicate), but given the non-idempotentHint and the presence of list_skills, this is a minor gap. The description is complete enough for an agent to call correctly.

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 all six parameters are documented in the schema itself. The description adds no new parameter-specific semantics beyond what the schema provides (e.g., it doesn't explain how tags or artifact_affinities are used in routing). Given full schema coverage, baseline 3 is appropriate; the description's mention of 'instruction text' aligns with the 'instruction' parameter but doesn't add extra.

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 clearly states the verb ('Enable') and direct resource ('one prompt skill') as a 'first-class capability binding', with a concrete outcome: the skill's instruction text becomes an instruction_only capability selectable by route_capabilities. It also names two siblings (disable_skill, list_skills) for lifecycle management, distinguishing this from them.

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 description gives clear context: when you want to enable a skill as a binding, and explicitly says to use disable_skill to remove it and list_skills to see what's enabled. It lacks explicit 'when not to use' or mention of alternatives for creating other binding types (e.g., create_capability_binding), but the sibling pair is clearly named.

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