read_symbol

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

With no annotations, the description carries the full burden. It discloses that the body is capped by VTS_SYMBOL_MAX_LINES and explains the signatureOnly parameter. It also implies read-only behavior, though it doesn't explicitly state it. Missing details on error handling or performance.

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 three sentences, each serving a distinct purpose: purpose, usage guidance, and parameter clarification. It is front-loaded with the key distinction and contains no unnecessary words.

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 the tool has 6 parameters, 100% schema coverage, and no output schema, the description covers the main purpose and usage context well. However, it does not explain the return format beyond 'span' or clarify the disambiguation logic for the 'path' and 'line' parameters.

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 100%, so baseline is 3. The description adds extra context for the signatureOnly parameter ('head only') and mentions the body cap (VTS_SYMBOL_MAX_LINES). No additional meaning added for other parameters beyond the schema.

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 it returns the source of a single named declaration (its span), not the whole file. It explicitly identifies itself as the read twin of replace_symbol_body, distinguishing it from sibling tools like find_references or goto_definition.

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 advises to use this tool when you need only one declaration's source, avoiding reading the whole file. It also references its counterpart replace_symbol_body. However, it does not explicitly list alternatives or when not to use it.

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