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

Read-only safety is already covered by readOnlyHint=true. The description earns credit by adding behavior the annotation does not: UTC date format with on-or-after matching semantics, the mutually exclusive archived/contact/deceased constraint, and the underlying API path (people/search). Pagination behavior itself is left to the schema.

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 content is front-loaded with the core action and example before the key list, and nothing is wasted on filler. The long comma-separated key enumeration makes the second sentence dense and run-on, slightly reducing scanability.

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 read-only search with a free-form nested search object and no output schema, the definition supplies the examples, key vocabulary, date semantics, and exclusion rule an agent needs to call it correctly. The only material omission is the relationship to elvanto_list_people and elvanto_get_person for disambiguation.

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?

Although schema coverage is nominally 100%, the required `search` object is free-form (additionalProperties with no key enumeration), so the schema alone does not tell an agent which keys are legal. The description supplies the entire searchable-key vocabulary, date formatting, and the custom_<field id> pattern, which is genuinely additive rather than redundant.

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 opens with a clear verb+resource ("Find people matching field values") and immediately grounds it with concrete example payloads, so an agent knows exactly what the tool returns. It stops short of naming a sibling such as elvanto_list_people to disambiguate when a plain listing should be used instead.

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?

It gives one real operational rule not found in the schema ("Use only one of archived / contact / deceased at a time") plus match-semantics for dates. However, it never states when this search should be preferred over elvanto_list_people or elvanto_get_person, leaving sibling selection to inference.

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