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

Annotations already declare readOnly/idempotent/non-destructive, but the description adds provenance and freshness context the annotations cannot: prices were checked on official pages, carry a checked date, and entries marked "estimate" are unconfirmed. That directly tells an agent how much to trust the returned numbers.

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 sentences, front-loaded with the trigger and return shape, with the trust caveat last where it belongs. The service enumeration is slightly long but earns its place by scoping coverage.

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?

There is no output schema, so the description must describe returns, and it does: per-service plans, USD monthly and yearly list prices, and the plan key. Combined with the freshness caveat, an agent has everything needed to call and interpret this tool.

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?

Zero parameters, so the baseline is 4. The description explicitly says "No input," which confirms the agent needs to supply nothing, though there is no further semantic ground to cover.

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 ("List AI subscription plans") and enumerates the covered services plus what each entry contains (plans, USD monthly/yearly list prices, key). This clearly separates it from the sibling aitab_total_ai_subscriptions, which sums rather than lists.

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 an explicit trigger ("when the user asks what AI plans cost"), an explicit sequencing rule ("before aitab_total_ai_subscriptions to look up plan keys"), and an explicit preference against relying on remembered prices. Both when-to-use and the alternative are named.

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