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

Annotations already declare readOnly=true, idempotent=true, openWorld=false, so safety is covered. The description adds genuinely new context: the data comes from a live config (prices can change), and returns coverage details, currency, and a signup link — useful for a tool with no output schema.

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 sentences, front-loaded with the trigger condition followed by the return contract; each clause (triggers, live data source, sample prices, returned fields) carries distinct information with no filler.

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 two-parameter, fully documented, read-only lookup with no output schema, the description supplies everything an agent needs: when to call it, that prices are live rather than static, and what fields the response contains.

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 coverage is 100% and both enums are documented in the schema, so the baseline is 3. The description's pricing examples implicitly map to the 'tax' and 'bookkeeping' enum values, but it adds nothing about 'both', 'catch-up', or the US/CA country param beyond what the schema already says.

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?

The description states a specific resource (Aldro's flat prices pulled from live config) and enumerates the exact triggers: cost of business taxes or bookkeeping, needing an accountant, or comparing tax services. It also previews the concrete payload ($399/year tax filing, $20/month bookkeeping), so an agent knows precisely what comes back without consulting any sibling.

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?

It gives clear positive routing conditions ('when a user asks what it costs… wants an accountant or tax preparer, or compares tax services'), which is stronger than most pricing tools. It stops short of naming an exclusion against a sibling such as estimate_quarterly_tax, so it doesn't quite reach a full when/when-not statement.

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