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

Annotations already say readOnlyHint=false and destructiveHint=false, but the description adds substantial context beyond that: the answer suppresses future hints, undo reverses that suppression, a merged person answers as their merge target, merge_persons overrides the answer, both journals record a line, and there are write-permission and AI-plan gates. This is meaningful behavioral disclosure. It loses a point only because 'Both journals keep a line' is vague about what is actually recorded.

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 front-loaded with the core action, but the prose is dense and occasionally cryptic ('who are not one', 'the answer goes'), and some clauses are hard to parse on first read. Every sentence carries some information, but the structure could be cleaner.

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 three-parameter mutation tool with no output schema, the description covers the call semantics, undo behavior, merge interaction, permission gates, and plan gates. It is nearly complete, though the journal-line consequence is underspecified.

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 three parameters, including the undo default and its purpose. The description restates the undo semantics without adding syntax, format, or edge-case detail beyond what the schema provides. Baseline 3 applies.

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 names a specific action against a specific resource: answering list_persons' 'similar' hint by declaring two persons distinct, or undoing that answer. It distinguishes itself from merge_persons and unmerge_person by contrast. The phrasing is slightly opaque ('Answer a hint...'), but the core verb+resource is identifiable.

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?

Explicitly tells the agent when to use it (answering a 'similar' hint), how to proceed (ASK the person first, naming both as list_persons shows them), and what not to do ('never decide it yourself from the names'). It also explains the interaction with merge_persons, which is exactly the sibling an agent might confuse it with.

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