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

Annotations already declare readOnlyHint/destructiveHint=false, and the description's 'Read-only' merely restates that. It does add genuine behavioral context beyond the annotations: results are ordered oldest first, uncommitted work is included, and the output covers reverted attempts and their reasons — scope facts an agent cannot get from the hints alone.

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?

Front-loaded with the motivating question, then a dense but earned enumeration of returned artifacts with no filler sentences. The single long clause stack is slightly heavy but each element describes real output content rather than padding.

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?

There is no output schema, so the description carries the return-value burden and does so thoroughly — edits, intents, rationales, reverted attempts, notes, and uncommitted work — while also stating ordering. For a zero-required-param read-only tool, nothing an agent needs to call it correctly is missing.

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 all three parameters (path, symbol, repo_id) are already documented, including repo_id's fallback behavior. The description only restates the path/symbol pairing at a high level and adds no format or syntax detail, so baseline 3 applies.

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?

States a specific verb+resource — the history behind a path or symbol — and enumerates the exact payload (each edit with who/when/what, completed intents with rationales, reverted attempts, anchored notes). That content profile is unmistakably distinct from siblings like get_symbol (current code) or recall (agent memory), so an agent can route without opening a schema.

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?

Usage is only implied by the framing 'Why the code is the way it is,' which signals the rationale/history use case, plus the scoping rule that omitting a symbol covers the whole file. There is no explicit when-not-to-use or named alternative (e.g., versus get_symbol or blast_radius), leaving the agent to infer the boundary.

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