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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and closed-world, so the safety profile is covered. The description adds non-redundant context: this is an index/table-of-contents call whose value is knowing what topics exist, and it names the three topic areas so the agent knows what to expect. It does not add cost/pagination caveats, but with full annotation coverage that is minor.

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?

Two sentences, zero filler: the first defines the output shape, the second delivers the routing advice and the content preview. Nothing repeats the title or the annotations.

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?

A zero-parameter discovery tool with an output schema, so return values and pagination need no explanation. The description supplies exactly what the structured data cannot: why the agent would call this and what it leads to.

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?

Zero parameters, so the baseline is 4. The description correctly says nothing about arguments and instead spends its words on the semantic meaning of the returned list.

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?

Uses a specific verb+resource ("List the available Tessryx guides") and even characterizes the payload ("topic + what each covers"). It implicitly separates itself from get_guide, which fetches a single guide, though the distinction is carried more by the usage sentence than by the purpose statement itself.

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 names the alternative (get_guide) and the trigger condition ("before building something you're unsure how to model"), then lists what the guides actually cover so the agent can judge relevance without calling it first. This is a complete when/when-not/alternative routing instruction.

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