Upstream blockers

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

The description adds behavioral detail beyond the annotations: it states the output format (one id per line) and ordering (dependency order), and specifies it works over 'blocks edges.' These details are not present in the annotations (which only cover readOnly, idempotent, non-destructive). No contradiction, and the extra context is useful.

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?

The description is two concise sentences, with the core function front-loaded followed by a useful comparison to related tools. Every phrase contributes meaning; there is no filler or redundancy.

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?

Given a single parameter, full schema coverage, and annotations that establish safety, the description provides enough context to call the tool correctly: it explains what is returned and how, and notes related tools for alternative needs. It is complete for practical use.

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?

The schema already covers the single parameter 'id' with a description and examples, and coverage is 100%. The tool description adds no additional parameter-specific semantics beyond what the schema provides, so the baseline of 3 is appropriate.

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 clearly states a specific function: list every node that must finish before a given node starts, returned as one id per line in dependency order. It also names alternatives (impact, path) and differentiates itself from them, so an agent can identify this tool's unique role among many siblings.

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 description explicitly explains when to use it (for upstream blockers) and explicitly contrasts with alternatives: 'impact is the downstream mirror; path shows the whole critical chain.' This gives clear guidance on when not to use it and routes the agent to the correct sibling for other dependency queries.

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