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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the read-only nature is covered. The description adds valuable context beyond those: the auth requirement ('OAuth or supported scoped credential'), the cost ($0.05, API key required), and the resolution behavior ('name resolved via aliases'). This meaningfully enriches the behavioral profile without contradicting the annotations.

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 two sentences, with the core purpose front-loaded and the invocation/auth/cost details compressed into one follow-up sentence. No filler, every word adds information. It is appropriately sized for a simple list tool.

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?

With an output schema present and full parameter documentation, the description covers the essential call contract: what it returns (aliases), how to specify the target, auth requirements, and cost. The only minor gap is that it doesn't explicitly state the scope of 'canonical' (e.g., whether it returns all aliases or only primary ones), but this is a minor ambiguity given the tool's simplicity.

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 schema already provides full descriptions for both parameters (100% coverage), so the baseline is 3. The description adds semantic value by explaining how the parameters relate: 'Pass person_id or name (resolved via aliases)' indicates that name is a fallback and that alias resolution is a mechanism. This clarifies the intended usage beyond the individual schema entries.

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 states a specific verb ('List'), a concrete resource ('canonical aliases (nicknames) for a CRM person'), and clarifies the input modes. Among the many get_* siblings, the purpose is immediately clear and not confused with other person-related tools like get_person_interactions or get_person_transactions.

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 explains how to invoke it ('Pass person_id or name') and adds the nuance that name is resolved via aliases. However, it does not give explicit guidance on when to choose this tool over alternatives like get_people or get_person_interactions, nor does it mention any exclusions or prerequisites beyond auth. Some context is implied by the tool's niche, but it lacks explicit routing.

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