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

Annotations declare readOnlyHint=false and idempotentHint=true, and the description adds the crucial non-annotation detail of credit consumption and its repeat-free behavior, plus the scope limit on email. It does not say what happens on an invalid or already-deleted creatorId, but the expensive/irreversible aspects an agent needs are covered.

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 tight sentences: what it returns, what it costs, and what it does not do. Each sentence carries distinct decision-relevant information with no repetition of the title or schema.

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 compensates by enumerating the returned fields, and it covers the two things an agent would otherwise get wrong: the credit charge and the email omission. For a one-parameter, non-destructive tool this is complete.

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% for the single creatorId parameter, and the schema already states it comes from search_creators results. The description adds no further meaning such as format or failure modes for the id, so the baseline of 3 applies.

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 ('Unlocks the creator') and enumerates the payload ('handle, profile link and recent video titles and links'), which is far more informative than the title alone. It does not differentiate itself from the sibling get_creator, leaving ambiguity about what that tool returns versus what unlocking adds.

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 concrete cost guidance ('0.5 credits the first time for each creator; unlocking again is free') and an explicit exclusion with a named alternative ('It does not reveal the email address; use reveal_contact for that'). Missing is any statement about when to choose this over get_creator or search_creators.

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