Explain

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

With no annotations, the description carries the behavioral disclosure burden. It communicates that this is a single aggregated call combining multiple data sources and that it can replace Read, which is meaningful behavioral context. It does not explicitly state read-only, but the nature of 'onboarding' and 'explain' makes mutation highly unlikely.

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?

Two dense sentences, no filler. The core use case is front-loaded, and the verbosity guidance is a practical addition that earns its place.

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?

The description is nearly complete for a two-parameter read-style tool with an output schema. It covers purpose, use case, an alternative tool, and parameter usage. The only notable gap is a lack of explicit routing against search/find_symbol in the provided sibling list.

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 baseline is 3. The description adds value by explaining when to use verbosity='summary' versus 'full', which goes beyond the schema's simple 'Output detail level' text. It does not add much for symbol_name, but the schema already sufficiently defines it.

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 states a specific verb ('explain'), a specific resource ('an unfamiliar symbol'), and the concrete components of the result: call-graph relationships, related code via semantic search, and quality metrics. This clearly distinguishes it from sibling tools like search or find_symbol.

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 to use it for onboarding to an unfamiliar symbol and points out that Read is often unnecessary, giving clear context. However, it does not explicitly state when a sibling tool like search or find_symbol should be preferred instead.

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