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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds value beyond them: provenance ('generated from the same source as the public pricing page'), identifier stability, and explicit cache-safety guidance, which is real behavioral context for an agent.

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 dense sentences, front-loaded with what is returned, followed by the billing constraint and cache note. Every clause carries information, though the tier enumeration and price-type listing make it heavier than strictly minimal.

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 convey the return shape — and it does: both tracks, tier names, yearly list price plus founding-cohort price, and feature list, along with the yearly-only billing constraint. An agent can use this without further documentation.

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 correctly implies a no-argument call and instead spends its words on the returned structure, which is the right trade-off for a parameterless lookup.

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?

Names a specific verb+resource ('Return the canonical two-track subscription matrix') and enumerates exactly what that resource contains (restaurant vs Hotels tracks, their tier names, yearly prices, feature lists). No sibling touches pricing, so it is trivially distinguishable from all 25 other tools.

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 clear context for use — it is the canonical pricing source — and adds an actionable qualifier ('stable identifiers — safe to cache'). It does not state when NOT to use it, but no sibling offers pricing data, so no routing alternative exists to name.

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