get_subscribe_link

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

The description discloses that this is a static local response with no API call and cannot be rate-limited, which adds meaningful behavior beyond the annotations. It also specifies the return fields and instructs the agent to hand the URL to the user. No contradiction with annotations found.

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 well-structured: it starts with the primary purpose, then adds usage triggers, behavioral details, return information, and usage caution. Every sentence provides meaningful guidance without redundancy.

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 simple static tool with one optional parameter and an output schema, the description covers all necessary operational context: when to call, what happens, and what the agent should do with the result. There is no missing information that could lead to incorrect invocation.

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 single optional parameter tier is fully documented in the input schema, including the enum value 'pro' and its meaning. The description mentions the pro tier context but does not need to add more because schema coverage is 100%. This is a case where the schema correctly carries the parameter details.

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?

State a specific action: retrieving the subscription URL for FreightUtils Pro. It explicitly ties to higher API limits and clarifies the condition when it is relevant. The distinction from sibling calculator/lookup tools is clear.

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 explicit when-to-use guidance: when the user asks about upgrade/pricing or after a 429 rate_limited error. It also tells the agent what not to do (agents must not complete subscription), which is clear and actionable.

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