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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false. Description confirms these and adds important behavioral details: 'Returns teasers only, never full text' and 'on invalid, missing, or malformed input this tool never raises a protocol error — it returns {"error": ...}'. No contradiction.

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 structured with a front-loaded sentence stating core purpose, followed by an example, usage guidance, error behavior, and a retry note. No redundant or off-topic content. Every sentence serves a purpose.

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?

Simple tool with one parameter, good annotations, and output schema present. Description covers purpose, input, output structure, limitations, error handling, and safe retry. No gaps remain for an agent to invoke incorrectly.

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 a clear description for the single parameter 'slug'. The description adds a concrete example input and output, which helps but does not significantly extend the schema's own documentation. Baseline of 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?

The description starts with a clear verb and resource: 'Preview one product: metadata, persona teaser, and paid-skill teasers.' It differentiates from siblings by stating it returns teasers only, never full text, and explicitly names alternatives like get_full_persona and get_free_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?

Explicitly states when to use: 'Use to judge a product before committing.' Also tells when not to use: 'Not for the complete persona or skill bodies... and not when the caller wants instructions they can act on now (get_free_skill).' Provides error-handling guidance and retry safety.

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