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

readOnlyHint=true already tells the agent this is a safe, non-mutating read, so the description's burden is lighter. It adds the useful detail that extra fields are opt-in, but says nothing about behavior when the id is invalid, permission requirements, or return shape.

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?

One tight sentence with the primary action and optional fields front-loaded, followed by a short API-path note. No wasted words, though the endpoint reference is marginal value for an agent.

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 2-param read tool with annotations covering safety, the definition is mostly adequate, but with no output schema the description gives no hint of the returned person shape or which fields come back when 'fields' is omitted.

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 description coverage is 100%, so both parameters are already fully documented in the schema, and the description's short field examples add no meaning beyond the schema's much longer list. Baseline 3 applies when the schema does the work.

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?

States a specific verb (fetch) and resource (one person) scoped by id, which inherently separates it from the list/search siblings. The added API reference (people/getInfo) reinforces intent, so an agent can select it without inspecting either schema.

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 id-scoped phrasing implies you use this when you already have a person id, but no alternative is named (e.g. elvanto_search_people or elvanto_list_people for discovery). Usage is inferable rather than stated, so it lands at minimum-viable.

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