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

Annotations already convey that the operation is mutating, destructive, and idempotent. The description adds no further behavioral details about overwrite semantics, validation, or side effects.

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 repeats the same phrase twice and includes an unexplained 'Guidance:' and '| context' fragment, adding noise without providing useful information.

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?

Basic callable context is present: the resource and required parameters are identified. However, details about the update effect, return behavior, prerequisites, and usage scenarios are 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?

The schema covers both parameters with basic descriptions. No additional semantics are provided, such as whether points_count replaces the total or represents an incremental change, or what units/format are expected.

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?

Clearly specifies an update action on a user's loyalty points, with user_id and points_count in the schema. The update verb distinguishes it from read-only tools like shop_get_loyalty.

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?

No guidance is provided on when to use this tool instead of alternatives such as shop_get_loyalty. It does not clarify conditions for updating, whether points_count is an absolute value or delta, or any prerequisites.

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