lean_declaration_file

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

With no annotations, the description carries the full burden. It discloses important behavioral traits: the symbol must already be present in the file, the tool returns file contents or an error message, and files can be large. However, it does not elaborate on potential side effects (e.g., no edits), error conditions beyond symbol absence, or how it resolves the file path. It adds some value but is not exhaustive.

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 and well-structured: a one-sentence summary, a short note block with warnings, and a clear Args/Returns layout. Every sentence contributes value—the note about using hover info is especially useful. No fluff 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?

For a 2-parameter tool with a string-or-error return, the description covers the key aspects: what it does, how to use it safely (hover first), required argument semantics, and return type. It could mention why to prefer this over lean_file_contents or how it handles the file lookup when the symbol appears in multiple files, but overall it is complete enough for an agent to use correctly.

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 0%, meaning the description must compensate. It does: file_path is specified as an absolute path, and symbol is described as case-sensitive and the symbol to look up. This adds practical meaning beyond the bare schema types and titles, though it could go further with path format examples or handling of multiple declarations.

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 a specific verb+resource: 'Get the file contents where a symbol/lemma/class/structure is declared.' This clearly distinguishes it from siblings like lean_file_contents (which likely just reads any file) and lean_hover_info (which gives hover details). The scope is unambiguous.

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 usage note explicitly recommends using lean_hover_info before this tool and warns about large files, providing clear context. It doesn't explicitly state when NOT to use it or compare to alternatives, but the prerequisite guidance is actionable and helps select this tool correctly.

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