Explain file change

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

No annotations are provided, so the description carries full burden. It states 'Side effects: none beyond database reads,' and mentions failure modes, covering key behavioral traits beyond the schema.

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 well-structured with clear sections (Purpose, When to use, Inputs, Side effects, Output, Failure modes). Every sentence is informative, and there is no 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?

Given the presence of an output schema (indicated in context signals), the description appropriately omits return value details but covers purpose, usage, inputs, side effects, and failure modes, making it fully contextual.

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%, but the description adds context: 'file_path identifies the repo-relative file; limit caps evidence volume; include_narrative adds a deterministic cited summary.' This enriches the schema definitions.

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 'Explain why a file may have changed using stored changesets, code graph entries, snapshots, and related messages.' It uses a specific verb and resource, distinguishing it from siblings like get_changeset_detail which focuses on a single changeset.

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 explicitly says 'call during code review, bug triage, or handoff recovery when a file path needs historical context.' This provides clear context for when to use the tool, and the failure modes section helps avoid misuse.

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