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

Annotations already declare read-only, idempotent, non-destructive. The description adds that it 'never raises a protocol error' on bad input (instead returning an error object), which is a critical behavioral detail beyond annotations. Minor deduction because the description claims 'FREE' and 'no plan required' – these are access details, not strictly behavioral traits, but fair contextual extras.

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 reasonably concise given the information density. It front-loads the key action and includes a clear example. A few sentences are dedicated to error behavior and alternative tool comparison, which are valuable. Minor redundancy with 'FREE' and annotation duplication, but overall efficient.

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?

Given the tool's simplicity (1 required param, no nested objects), output schema exists, and annotations cover safety profiles, the description is comprehensive. It explains the single output, error format, correct slug source, and how to fix errors. No gaps remain for agent decision-making.

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% and schema already defines 'slug' with a description. The description adds an example value ('smb-ops-desk'), clarifies it must be exactly from list_products, and illustrates the typical input/output. This adds value beyond the schema, but since schema coverage is already high, a 4 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?

The description clearly states the tool loads a 'product's free gateway skill' with 'complete instructions' and returns a specific JSON shape. It also distinguishes itself from the sibling get_full_skill, which is for paid, named skills.

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 says when to use: 'Use when the caller wants usable instructions immediately.' And when not: 'Not for the product's other skills.' Contrasts with get_full_skill and mentions a paid plan requirement for the alternative. Provides error recovery guidance by showing the error pattern and suggesting list_products.

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