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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is clear. The description adds useful access context by stating the guides are public, free to read in full, and require no authentication—information not present in the annotations. This goes beyond what the structured fields provide.

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 a single, well-structured sentence that front-loads the core action and resource, then adds valuable context about content type and access. Every clause earns its place: public scope, evidence-based grounding, cross-book nature, and no-auth requirement. There is no redundancy or filler.

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 parameterless list tool with an output schema and readOnly annotations, the description is complete. It tells the agent what will be listed, where it is published, what kind of content it is, and that no authentication is needed. There are no gaps that would prevent correct invocation or interpretation.

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?

The tool has zero parameters, so the schema provides no parameter semantics to supplement. The description appropriately focuses on what is being listed rather than on parameter details, which are irrelevant here. The baseline of 4 applies because there is nothing for the description to clarify.

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 begins with a specific verb ('List') and names the exact resource ('public, grounded capability guides published on performix.app/guide'). It also distinguishes guides from books by explaining they are 'cross-book model[s]' of evidence for individual executive capabilities, which separates it from list_books and get_book. The example capability ('leading an R&D team') further clarifies the content domain.

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 clearly conveys the context for using the tool: listing publicly available guides, with no authentication required. It does not explicitly name when to use get_guide or list_books instead, but it gives enough contextual signals ('list', 'guides', 'public') for an agent to make a reasonable selection among siblings.

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