Read File

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

Annotations already declare readOnlyHint=true and destructiveHint=false, covering the safety profile. The description adds the line-number output behavior and the text-file-only scope, which is useful context. It does not explain behavior for missing/binary files, but that is a minor gap given annotation coverage.

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 sentences with no fluff: the core action and output format are front-loaded, followed by a single high-value usage warning. Every sentence 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?

For a read-only file tool, the description is nearly complete: schema covers all parameters, annotations cover safety, and the line-number aspect covers the return format. It doesn't mention edge cases like binary files or missing files, but those are not critical given the tool's simplicity and the existing documentation.

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 every parameter is already documented. The description adds no parameter-specific meaning, which is acceptable because the schema carries the burden. Baseline 3 is appropriate.

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 ('Read'), resource ('a specific text file'), and a distinctive output trait ('with line numbers'). The 'text file' qualifier helps differentiate it from sibling view_image, and the action is clear.

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 gives explicit when-not guidance: 'Avoid rereading files after write/edit/apply_patch unless exact final content is needed.' This is practical and actionable, though it does not name an alternative tool to use instead, so it falls just short of a full when/when-not/alternatives statement.

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