source_read

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

With no annotations provided, the description carries the full disclosure burden and does disclose key behavioral traits: it is read-only and does not require an auto backup. This gives the agent important safety context beyond a mere action. It does not mention error handling or return format, but for a read tool these are minor gaps, so a 4 is warranted.

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 one compact sentence with a parenthetical behavioral note. Every word adds value: the verb/resource pair is front-loaded, and the read-only/backup note provides essential safety information without clutter.

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?

This tool has no output schema, no annotations, and 0% parameter schema coverage, so the description must carry more weight. It omits behavior for start_line/end_line (inclusive bounds, default end behavior, interaction with null), error conditions for missing files, and the exact return format beyond 'line numbers.' These are notable gaps for an agent to invoke the tool correctly across use cases.

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 0%, so the description must compensate for the three parameters. While 'source file' maps to the file parameter, the description does not explicitly explain start_line and end_line semantics at all; 'with line numbers' only hints at output formatting, not range selection. The agent must rely on naming conventions, which is insufficient for this coverage gap.

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 action and resource: 'Read a source file with line numbers.' The verb 'Read' clearly distinguishes it from sibling tools like source_edit and source_search, and the mention of line numbers adds specificity without ambiguity.

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 parenthetical 'auto backup not needed; read-only' provides clear context for when to use this tool over a mutating sibling like source_edit, implying safe, non-destructive reading. However, it does not explicitly name alternatives or stipulate when not to use them, so it stops short of a 5.

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