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

Annotations already declare read-only safety, and the description adds substantial context beyond them: two-tier search order, free/instant vs free-with-hidden-emails, the 50-profile page cap, and the one-Contact-Finder-charge cost model for email reveal. That is exactly the behavioral/cost detail annotations cannot convey.

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 purpose, then scope, examples, email constraint, and the pagination pointer in a compact sequence. Each sentence carries distinct, actionable 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?

With no output schema, the description steps in to describe the return shape (up to 50 profiles, emails hidden) and the cost of revealing emails, plus the pagination tool. An agent has everything needed to call and interpret it.

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 50%: query is documented in the schema, but limit (default 50, max 200) is undocumented there. The description mentions 'up to 50 profiles' and the page size but never clarifies what the limit parameter controls, so it only partially compensates for the gap. Baseline 3 for partial coverage.

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 ('Search for contacts by title, company, or query') and explains the two-phase scope (saved Xmagnet contacts first, then a prospecting page). It is highly concrete but never explicitly distinguishes itself from the closely named sibling search_crm_contacts, so an agent lacks a direct sibling contrast.

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 explicit routing: saved-contacts-first behavior, concrete query examples, a clear statement that emails are excluded and that find_email should be called instead (with the Contact Finder cost), and a pointer to load_more_contacts for pagination. When-to-use and the alternative path are both spelled out.

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