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

The annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false. The description adds useful behavioral context beyond that: results are capped at 10 matches and each match includes its campaign, which shapes how the agent should interpret the response.

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 short sentences, front-loaded with purpose and immediately followed by scope and result shape. Every clause adds useful 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 simple one-parameter lookup with complete schema coverage, rich annotations, and no output schema, the description supplies the key missing return-shape behavior: up to 10 matches and campaign association. Nothing critical for correct invocation appears to be missing.

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 schema has 100% description coverage and fully documents the single email parameter, including that it accepts an email fragment. The description's '(or part of it)' largely repeats that, adding no syntax, matching rules, or additional parameter meaning, so the 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?

The description gives a specific verb and resource (find leads by email) and states the search scope (across ALL campaigns) plus partial-match behavior. It helps distinguish a broad email-based lookup from single-lead tools like get_lead, but it never explicitly differentiates itself from sibling search/list tools such as get_lead_search or list_leads.

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?

Usage is implied: use this when searching by email or an email fragment across campaigns. There is no explicit when-not guidance, no named alternatives, and no prerequisites, so an agent must infer when to choose this over get_lead, get_lead_search, or list_leads.

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