Blast radius of changing a symbol

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

With no annotations, the description carries the full burden of behavioral disclosure. It reveals that the tool returns transitive upstream callers, separates production callers from tests, and treats an empty test list as a signal that the change is unguarded. This goes beyond a generic 'impact analysis' phrase, though it doesn't discuss parameters, output format details, or potential performance costs.

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 sentences, front-loaded with the core purpose, and every clause adds value. The warning about empty test lists and the 'check before editing shared code' guidance are compact and actionable without unnecessary fluff.

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?

Despite having no output schema and sparse parameter docs, the description covers the essential output structure (production callers vs tests) and provides interpretation guidance (empty test list = unguarded). It leaves minor gaps around symbol formatting and depth semantics, but the schema covers depth, and the core use case is well specified.

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 only 33% because only 'depth' has a description. The tool description does not explain the meaning of 'symbol' (e.g., whether it needs a fully qualified name) or 'repo' (e.g., optional or default repository). Since coverage is low, the description should compensate, but it only refers generically to 'this symbol.'

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 uses the direct question 'What breaks if this symbol changes' and clearly states the resource (a symbol) and the specific output (everything transitively upstream, split into production callers and tests). It distinguishes this from sibling query tools like who_calls or what_it_calls by emphasizing transitive upstream impact and testing coverage.

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 gives clear usage context: 'check this before editing shared code.' It implies this tool is for pre-edit impact assessment and even signals when to be cautious (empty test list means unguarded change). It doesn't explicitly contrast with siblings, but the 'before editing shared code' instruction provides a practical trigger.

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