repo_read

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

Annotations already declare readOnlyHint and idempotentHint, so the description only needs to add context beyond those. It does add the UTF-8 text file requirement and the bounded line range behavior, which is useful. However, it does not disclose error behavior, encoding handling, or edge cases like out-of-bounds lines, so it only partially covers the burden with the low bar set by annotations.

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 a single, tight sentence that states the action and key constraints without filler. It is appropriately concise, though it could front-load the parameter semantics to be more useful. No excess words, so it earns a 4.

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 tool with four parameters (one required), no output schema, and zero schema descriptions, the description is minimal. It does not explain the start_character parameter, line indexing conventions, file-not-found behavior, or how bounds are interpreted. An agent cannot reliably call this tool correctly without additional inference, so completeness is low.

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?

The schema has zero descriptions for all four parameters, so the description must compensate. It only mentions a 'bounded line range', which explains start_line and end_line at a high level, but leaves start_character entirely unexplained, and doesn't clarify whether lines are zero-based, inclusive, or what happens with missing bounds. This is insufficient given the 0% schema coverage.

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 a specific verb (read), a precise resource (a bounded line range from a UTF-8 text file inside the target repository), and the constraints (bounded, UTF-8, repository-scoped). This distinguishes it from siblings like repo_search or repo_snapshot without needing to inspect schemas.

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 implies usage for reading a specific file's lines but does not explicitly state when to use this versus alternatives like repo_search, repo_snapshot, or codex_diff. There is no when/when-not guidance or named sibling, leaving the agent to infer based on the verb.

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