Update People

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

Annotations only declare openWorldHint=false and destructiveHint=false; the description adds genuinely non-redundant behavior: all-or-nothing atomicity ('Everything applies, or nothing does if any entry fails') and reversibility ('undo reverts it all in one step'). Minor tension remains, since link removal is a data-deleting act under destructiveHint=false, but the transactional and undo semantics are the useful additions.

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?

Four short sentences, front-loaded with purpose and ending with the sibling redirect. Dense but every clause carries information; the link-direction sentence is slightly cryptic in phrasing but earns its place.

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?

An output schema exists so return values need no explanation, and the description covers the remaining agent-critical facts: what mutations are supported, atomicity, undo-ability, link directionality, and the alternative for adding people. Nothing needed to invoke it correctly is missing.

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 coverage is only 33%, so the description must compensate, and it does for the highest-risk parameter: 'Each link reads "relative_id is person_id's relation"; set remove=true to remove it' disambiguates the direction of the relationship, which the schema's one-line 'What relative_id is to person_id' only partly covers. The ordering note ('details and renames, then links') also clarifies intra-call sequencing that the schema does not express.

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 opening sentence names a specific verb and scope: 'Change many existing people at once: details and renames, then links to add or remove.' It also explicitly differentiates from the sibling add_people ('To add new people, use add_people'), so the agent can route without opening 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?

'Use for one or many person updates or relationship changes' gives clear context and singles out the add case as belonging elsewhere. It stops short of explicit exclusions for other mutation siblings (merge_people, remove_person, set_tree_members), which would have made the routing complete.

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