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

Annotations only declare destructiveHint=true, so the description usefully adds that "Only the fields you pass change" (PATCH-style partial update semantics) and that username, password and login status are off-limits. It does not cover permissions, rate limits, or the return shape, but it adds real behavioral context beyond the destructive flag.

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?

Two compact sentences with the core edit semantics front-loaded and zero filler. The prohibitions are stated as a single tight clause rather than a sprawling list.

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 14-parameter mutation tool with a nested fields object and no output schema, the description covers the essential behavioral facts: partial-update semantics, the forbidden username/password fields, and the Elvanto endpoint. Return values are not described, but with no output schema that is a minor gap.

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 the schema already documents all 14 parameters including the nested fields object. The description only loosely groups them ("name, contact info, category, flags, family"), adding grouping value but no syntax or format detail beyond the schema — the correct baseline when the schema does the heavy lifting.

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 ("Edit") and resource ("an existing person's details") and enumerates the editable field groups — name, contact info, category, flags, family, extra fields. The word "existing" cleanly separates it from the sibling create_person, so an agent can route without opening the 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?

Gives clear context for when to use it (editing an existing person) and states a scope limit (cannot touch username/password/login status), but it never names an alternative sibling such as create_person for new people or get_person for reads. The usage context is clear but the when-not-vs-sibling routing is left implicit.

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