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

Annotations already provide readOnlyHint, idempotentHint, and destructiveHint. The description adds value by explicitly stating 'Every call is read-only and idempotent', clarifying error behavior (returns error JSON, never protocol error), and asserting retry safety. No contradictions with annotations; the description reinforces and extends the structured hints.

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?

Description is well-structured: purpose first, then example, usage guidelines, error behavior, and idempotency statement. Each sentence adds distinct information. A minor length reduction could be possible (e.g., merging some sentences), but it is not verbose and front-loads key 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?

For a tool with 2 clearly documented parameters, comprehensive annotations, and an output schema, the description covers all necessary aspects: purpose, usage boundaries, error handling, retry safety, and relationship to siblings. No gaps are apparent; the description is fully sufficient for correct tool invocation.

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% with detailed descriptions for both slug and skill_name. The description provides a typical input example ('{"slug": "curriculum-architect-hs", "skill_name": "unit-planner"}') which adds illustrative value but does not introduce new semantics or constraints beyond the schema. Baseline 3 is appropriate given high schema coverage.

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?

Description clearly states the tool loads 'one paid skill's complete instructions from a product', specifies it is premium/license-restricted, and provides an example input-output. It distinguishes itself from sibling tools get_free_skill and get_full_product by noting differences in scope and licensing. The verb 'load' and resource 'paid skill's complete instructions' are specific and unambiguous.

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 tells when to use ('when the caller wants one specific paid skill') and when not to use ('Not for the free gateway skill' and 'not for every skill at once'), naming the alternative tools. It also provides guidance on error handling and retry safety, covering both correct and incorrect usage scenarios.

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