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

Annotations already declare readOnly, idempotent and non-destructive, so the safety profile is covered. The description adds two genuinely useful behavioral facts the annotations do not: a 5-credit cost and a reliability caveat that results are candidates rather than a rights determination. It still says nothing about result volume, ranking, or ordering of 'earliest'.

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, zero filler, with the core purpose front-loaded and the cost caveat last. Nothing is repeated from the title.

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 lightweight read-only lookup with no output schema, the description covers purpose, cost and caveat but leaves the caller unsure how to construct inputs and what the candidate list looks like. Adequate but with real gaps given the zero parameter coverage.

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 0%, so the description carries the full burden. It hints at three input modes (title, description, TRYIT item) that loosely correspond to text/id/source, but never maps them to parameter names or says whether they are mutually exclusive or combinable, leaving the agent to guess.

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 ('Find the earliest known uploads of a clip/topic') and parenthesizes the output concept ('original-source candidates'). It implicitly distinguishes itself from search_content by targeting earliest-known originals rather than general retrieval, though it never names a 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?

Usage context is implied by the accepted input forms ('from a title, description or TRYIT item'), and 'Candidates, not a rights verdict' sets expectations. However it never says when to use this instead of search_content or similar_content, nor states prerequisites.

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