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

No annotations are present, so the description carries the transparency burden. It discloses the return contents (terms grouped by pillar, each with slug and definition) and the optional pillar filter, which is sufficient for a simple read-only listing operation. However, it does not explicitly state that it is read-only or describe potential errors, so a small gap remains.

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 three sentences, each adding distinct value: what the tool returns, when to use it, and when to use the alternative. It is front-loaded and contains no redundant or filler language.

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 (one optional parameter, no output schema, no annotations), the description is complete. It covers return values, grouping, optional filtering, and usage context relative to sibling tools, allowing the agent to correctly select and invoke the tool.

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 input schema already provides a complete description of the pillar parameter, including valid values and that omitting it returns all pillars. The description only says 'Accepts an optional pillar filter,' which adds no new semantic meaning beyond the schema. Baseline of 3 is appropriate given full 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?

The description clearly states the tool returns all published Arco Lexicon terms grouped by pillar, including slug and canonical short definition. It also differentiates from lookup_term by indicating when each should be used, making the purpose unmistakable.

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?

Explicit usage guidance is provided: 'Use this tool first when you do not know which term to look up' and 'Use lookup_term once you have identified the term you need.' This clearly tells the agent when to use this tool versus a specific alternative.

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