Symbol Definition

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

Annotations already provide readOnlyHint and idempotentHint. The description adds behavioral context: the tool returns a single deterministic declaration site (file, line, kind, snippet), and mentions caching via the bypass_cache parameter. This covers the main behavioral traits without contradiction.

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 concise: a single introductory sentence followed by three bullet points. It front-loads the core purpose and uses structured bullets for clarity. No extraneous information.

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 an output schema exists, the description adequately covers the tool's purpose, behavior, and use cases without requiring return value details. It mentions the output components (file, line, kind, snippet) and references sibling tools, providing sufficient context for an agent.

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 the baseline is 3. The description does not add significant new semantics beyond the schema descriptions for individual parameters. The overall context helps understand parameter usage (e.g., path filters), but no specific parameter details are enhanced.

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 explicitly states 'Return the single best deterministic declaration site for a known identifier.' It uses a specific verb ('Return') and resource ('declaration site'), and distinguishes from siblings by contrasting with symbol_search (ranked) and symbol_references (non-declaration usages).

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 lists three bullet-pointed use cases, including 'Jump straight to the canonical declaration' and 'Get one definitive answer rather than a ranked list.' It also explicitly mentions complementing sibling tools symbol_search and symbol_references, providing clear when-to-use guidance.

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