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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds real value beyond that: an explicit provenance guarantee — 'The surface never silently answers from local data' — and clarifies which database it reads (production or explicitly opted-in local). This explains the openWorldHint=false annotation usefully.

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 purpose, which is good. However, the middle section is rambling and grammatically awkward — 'Leads with what the buyer gets and how to act on it, then the mechanics:' — where 'Leads' is ambiguous (verb vs. noun) and the sentence structure is tangled. The description runs ~100 words and would benefit from tightening.

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 0-parameter meta tool with a rich annotation set and an output schema present, the description covers the essentials: what it does, when to use it, what it reads, and the built-in guarantees. It mentions 'the tools available' but doesn't enumerate them, relying on sibling context; this is a minor gap, not a blocker.

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 tool takes 0 parameters, so per the rubric the baseline is 4. There is nothing the description could add about parameters, and the schema (no properties) makes this unambiguous. No penalty applies.

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?

Front-loads a specific purpose — 'What GoodLeads is — call this to explain or vet us' — with a clear verb (explain/vet) and resource. Explicitly flags what it is NOT for ('to price a list, start with interpret_list'), distinguishing it from the same-named sibling. The meta-nature (describing the surface itself) is clearly separated from navigate/price/checkout 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 an explicit trigger ('call this to explain or vet us') and names an alternative for a specific scenario (interpret_list for pricing). It also tells the agent what the call will surface (database provenance, contract, available tools). It doesn't enumerate when-not-to-use cases against other siblings like explain_concept, but the core trigger and one key exclusion are clear.

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