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

Adds substantial context beyond the annotations: the auth requirement, the exact billing model (verified owner costs one unlock, named owner free, repeat unlocks free), the PECR flag on emails, and the TPS/CTPS distinction in dental results. The idempotentHint=true annotation is corroborated by the 'unlocking the same owner again is free' statement rather than contradicted.

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?

Front-loaded with the payload (name, phone, email) and then the cost/auth rules. Dense but each sentence carries information; the billing and TPS/CTPS sentences are long but earn their place.

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?

No output schema, yet the description names exactly what is returned (owner name, phone, public email, PECR flag) and covers cost, auth and follow-up obligations. An agent has everything needed to call it and interpret results.

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?

Only one parameter with 100% schema description coverage, so the schema already explains 'id'. The description adds the useful context that the id refers to 'a search result' for 'one business', but goes no further into format or sourcing. Baseline 3 is appropriate.

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: 'Reveal the owner's name, phone and any public email for one business from search.' The scope (one business, from search results) clearly separates it from siblings search, balance and coverage.

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 real preconditions: you must sign in to UK Leads, it spends from the desk's monthly allowance, and 'Screen every number before you call' plus the TPS/CTPS note guide downstream use. It stops short of explicitly naming when to prefer search or balance, but the context makes the ordering obvious.

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