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

Annotations already establish the safe read-only profile (readOnlyHint=true, destructiveHint=false). The description adds non-obvious behavior the annotations cannot convey: searches do not consume lead allowances, and returned emails are masked with plaintext access governed by existing permissions.

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?

Four sentences, front-loaded with what the tool does, then the routing rule, then non-obvious behavior. Every sentence carries information; the pagination sentence slightly overlaps the schema's documented limit/offset but still sets an overall cap.

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?

With no output schema, the description usefully discloses the return shape (masked emails) and the permission gating on plaintext, plus pagination behavior. It is complete enough for correct invocation, though it does not describe ordering or result-count semantics for pagination.

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%, so all six parameters (city, state, country, keyword, limit, offset) are already documented in the schema. The description only restates the filter dimensions and the limit/offset pagination with a 50-record cap, adding no syntax or format detail beyond the schema. Baseline 3 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?

States a specific verb (Search) plus resource (LastDatabase consumer email records) and enumerates the filter dimensions. It explicitly distinguishes itself from the professional/B2B contact tools, so an agent can route between search_consumer_emails and search_people/search_hot_leads without inspecting schemas.

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 a clear selection rule: 'Use this tool for consumer email discovery rather than B2B professional contacts.' That is explicit when-to-use/when-not guidance, though it does not name the actual sibling tool(s) to use instead for B2B.

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