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

Annotations already indicate a non-read-only, idempotent, non-destructive operation. The description adds value by clarifying partial-update semantics ('Only provided fields are updated') and by stating the return behavior ('Returns the updated persona object'). No contradiction with annotations.

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 a single focused sentence that front-loads the action and resource, lists the relevant fields, states the partial-update behavior, and notes the return value. Every clause 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?

For a straightforward update tool, this is largely complete: it names the fields, states partial-update semantics, and reports the return object despite no output schema. The main gap is not offering guidance on prerequisites like the persona existing or how errors are surfaced.

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 0%, so the description must compensate. It names the updatable fields, which helps, and clarifies that only provided fields are updated. However, it does not explain the required personaId parameter or provide any detail about formats, boundaries, or list item expectations beyond what the schema already shows.

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 starts with a specific verb and resource: 'Update a persona's...' and enumerates the exact mutable fields: name, description, pain points, goals, or objections. This clearly distinguishes it from create, get, list, and delete persona tools nearby.

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?

The usage context is implied by the verb 'Update' and the resource 'persona': use this when modifying an existing persona's fields. However, it does not explicitly mention alternatives or conditions, such as using create_persona when the persona does not exist yet.

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