List files changed

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

The readOnlyHint annotation already declares the operation safe. The description adds valuable context about output scope (file-level line counts, not the diff content), clarifying behavior beyond the annotation. It does not address pagination or errors, but the safety profile is covered.

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: the first states purpose, the second gives a pragmatic usage tip. Front-loaded, no redundant words, and 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 simple read-only list tool with annotations and a clear schema, the description covers core behavior and usage context. The absence of an output schema is mitigated by describing what is returned (files with line counts), making the tool's invocation and expected result reasonably clear.

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 67%, covering repo_slug and workspace. The required pull_request_id lacks a description, but its meaning is obvious from the name and context. The description adds no parameter-level detail, relying on the schema, which is adequate.

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 specifies the tool's function: listing files changed in a pull request with per-file line gains/losses, explicitly excluding the full diff. This distinguishes it from the sibling tool get_diff by saying 'without the diff itself.'

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 provides explicit usage guidance: 'Use this first on a large pull request to decide what is worth reading.' It gives a clear scenario but does not explicitly name alternatives or exclusions, though the contrast with get_diff is implied.

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