Subscribe Topic

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

Annotations already declare this is a non-read-only, non-destructive, non-idempotent mutation. The description adds meaningful context beyond that: subscription is personal ('Only affects you') and reversible via unsubscribe_topic. It does not clarify repeated-subscribe behavior despite idempotentHint=false, which would have been useful.

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?

Two short sentences, front-loaded with the action and its effect, followed by scope and reversal. No wasted words.

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?

A simple two-parameter mutation with full schema coverage, annotations, and no output schema. The description covers purpose, personal scope, and reversal. It leaves only minor gaps around repeated subscriptions and notification delivery details.

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%, with both course_id and topic_id documented including where to obtain them. The description adds nothing about parameters, so 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?

States a specific verb and resource ('Subscribe to a discussion topic') and immediately explains the effect ('notified about new replies'), distinguishing it from read-only topic tools like get_topic and list_topics.

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 identifies the inverse operation ('Reverse with unsubscribe_topic'), giving clear routing guidance. It does not state when not to subscribe or any prerequisites, but the use case is clear for such a simple tool.

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