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

With no annotations, the description carries the full behavioral burden, and it does add one valuable fact: results carry an SMTP-verified business email and only verified emails are billed. That is real cost/quality context. But it omits critical traits for a 10-parameter enrichment tool: whether execution is synchronous or async, how results are retrieved (the presence of a get_results sibling strongly hints at job-based retrieval), rate limits, and credit consumption per result.

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?

A single tightly written sentence with the core action front-loaded and the billing caveat appended. Nothing is wasted, though the brevity is partly achieved by omitting information the tool actually needs to convey.

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 10-parameter, zero-required, no-annotation, no-output-schema tool that likely runs as an async job (sibling get_results), the description is far too thin. It never explains how to combine niches/channels, how to retrieve results, or what a returned record contains beyond the email, leaving the agent to guess at invocation and follow-up.

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 only 40% (country, language, channels, only_new), leaving niches, location, per_niche, max_subscribers, min_subscribers, and only_with_email undocumented in both schema and description. The description adds no parameter-level meaning beyond restating the niche/channel duality, so it does not compensate for the coverage gap. 'niche' vs 'channels' semantics and the min/max_subscribers filter behavior are left ambiguous.

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 names a specific verb and resource ('Finds YouTube channels') and covers both operating modes (search by niche, or read explicit channels), which distinguishes it from generalist siblings like find_creators and find_linkedin_leads. It is clear what the tool does, though it does not explicitly contrast itself with the closest sibling.

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?

The parenthetical '(or reads given channels)' implies the two usage modes (niches vs channels), so an agent can infer which parameter set to supply. However, there is no explicit when-to-use guidance, no mention of alternatives among the many find_* siblings, and no prerequisites stated.

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