sources_of

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

With no annotations provided, the description carries the full burden. It discloses read-only behavior, describes the return shape (labeled nodes and edges), mentions truncation/frontier metadata, and warns that a missing path is not proof of absence. This is substantial, beyond minimal behavioral disclosure.

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 sentences, each earning its place: purpose and trigger, return content, and a critical caveat. The key action is front-loaded and there is 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?

For a simple read-only query with full schema coverage and no output schema, the description is largely complete: it covers purpose, output nature, and a non-obvious completeness caveat. It does not explain how limit/format shape the result or contrast with sibling flow tools, but those are minor given the schema and specificity.

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%, so the schema already documents sink, limit, and format. The description adds context for 'sink' by tying it to a selected candidate/sink, but it does not enrich parameter semantics beyond what the schema provides.

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 leads with a precise verb-resource pairing: a read-only reverse value-flow cone for a sink. It further specifies the operation's goal ('find values that may feed it') and distinguishes it from forward-flow tools by the word 'reverse' and 'cone' semantics.

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?

It explicitly says when to use the tool: after a candidate or sink is selected. It does not name sibling alternatives or state when not to use it, but the trigger condition is clear enough for an agent to select it.

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