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

Annotations already declare readOnlyHint and openWorldHint=false, so the description goes beyond them by disclosing cost ('Free'), exact-match matching semantics, cross-platform search scope, and the meaning of an empty result. It does not mention rate limits or result ordering, but nothing essential for correct invocation is missing.

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?

Three short sentences, front-loaded with the action and input form, then scope, then outcome semantics. Every clause carries distinct information: cost, matching rule, and empty-result meaning.

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, so the description correctly explains what comes back (a creatorId) and how to interpret the failure case (empty list means not in Creator River). For a single-parameter read-only lookup this is everything an agent needs.

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% and already documents the reference format with an example, so the baseline is 3. The description adds real meaning beyond the schema: matching is by exact handle, and the same handle is checked across every platform, which is not inferable from the parameter definition alone.

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 ('looks up a creator'), the input form (@handle or profile link), and the scope ('on every platform where that exact handle is in Creator River'). This distinguishes it clearly from discovery-oriented siblings like search_creators, browse_creators, and find_similar_creators.

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 concrete trigger: use when 'the user names' a creator by handle or link, and names the follow-on tools (get_creator, add_creator, reveal_contact) that consume the returned creatorId. It does not explicitly state the inverse case (use search_creators when the user describes rather than names a creator), which keeps it from a 5.

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