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

Goes well beyond annotations (destructiveHint=true, idempotentHint=true) by explaining exactly what is and isn't affected: live QUALIFIER steps re-evaluate, but already-passed leads are never re-scored. Also discloses that shared personas change every consuming flow at once — critical for a destructive mutation.

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?

Three tight sentences with the purpose first, then the non-retroactive behavior, then the shared-usage warning and plan requirement. No filler.

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?

Covers the mutation's scope, side effects, prerequisite check, and plan requirement for a destructive nested-object update with no output schema. The only gap is not enumerating which fields (title, description, criteria) can be changed.

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 100% and each criteria field is documented inline, including the personaId source ('from persona_list'). The description adds no parameter-level detail beyond the schema, so baseline 3 is appropriate.

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+resource: 'Change a persona's criteria', which separates it from persona_create/delete/get/list siblings. Minor understatement: the schema also allows updating title and description, which the description doesn't mention.

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 a clear precondition ('Check usageCount in persona_list first') and a plan gate (Pro or Agency), and frames the edit's blast radius across flows. It stops short of naming alternative tools for other persona operations, but the guidance is actionable.

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