Bite: is this past fix guarded by a test?

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

The annotations already declare readOnlyHint=true and openWorldHint=false, and the description reinforces this usefully by stating it is free, needs no key, never touches the user's files, and works on a copy. However, it omits the practical behavior an agent would want for a test-running tool: how long it may take and whether there are limits on how many commits can be tested.

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 example question is front-loaded and the answer shape is stated up front, so the reader gets the essentials immediately. The first sentence is long and carries several ideas at once, but no sentence is pure filler.

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, and the description compensates by describing the return shape (a short Yes/No/Partly answer followed by a block per commit with its id). Combined with the safety and mechanism notes, this is nearly complete for a read-only analysis tool, with only timing/limits unstated.

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 the schema already defines all three parameters, making 3 the baseline. The description adds some meaning by explaining how the question is matched (commit messages, changed file names, and named time ranges), which helps an agent phrase the question, but it says nothing extra about `last` or `folder`.

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 gives a specific verb-and-resource: it takes a plain-words question about an already-committed fix, locates matching commits, reverts them on a copy and runs the tests. The only gap is that it never mentions the sibling check_fix, so an agent cannot distinguish the two from the text alone.

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 context is clear: use it for fixes that are already committed, phrased in plain words. It also gives a recovery path ("If nothing matches, ask again with words from the commit message"), but offers no explicit when-not conditions or comparison to check_fix.

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