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

Annotations already declare readOnlyHint/destructiveHint, so the safety profile is covered. The description adds substantive behavior beyond that: search does not consume lead allowances, email/phone fields stay masked, plaintext access follows customer permissions, and per_page caps at 50. It does not describe result ranking or ordering, but the added operational context is rich.

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 primary action and filters, then usage guidance, then behavioral caveats in tight sentences. Every sentence carries either routing, safety, or limit 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?

There is no output schema, but the description covers the information an agent needs: filter scope, when to choose this over siblings, the no-allowance and masking behavior, permission gating, and pagination limits. Nothing essential is missing for correct invocation.

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 description coverage is 100%, so all seven parameters are already documented in the schema (including page/per_page defaults and bounds). The description restates the filter dimensions and pagination but adds no syntax, matching behavior, or format detail beyond the schema. Baseline 3 is correct when the schema does the heavy lifting.

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 verb (Search) and resource (LastDatabase mixed lead records) with the exact filter dimensions it accepts. It explicitly distinguishes itself from the dedicated B2B contact, consumer email, and phone datasets, which are distinct siblings (search_people, search_consumer_emails, search_phone_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?

It gives an explicit when-to-use: 'Use when the customer requests mixed lead data rather than a dedicated B2B contact, consumer email, or phone dataset.' This names the alternatives and the condition that selects this tool over them, leaving little to inference.

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