Update a changelog entry

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

The annotations are all false flags, providing little positive safety information, so the description carries most of the behavioral burden. It adds meaningful context: omitted fields are left untouched, the entry's original date is preserved, and the tool is intended for corrections, not history rewrites. This is useful beyond what annotations alone convey, though it does not cover response or error behavior.

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?

Three sentences, each earning its place: the first states the core operation and scope, the second explains partial-update semantics, and the third provides a usage guardrail. The most important information is front-loaded, and there is no filler or redundant restating of the tool name.

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 small three-parameter edit tool with no output schema, the description covers the essential invocation context: ownership, editable fields, partial-update behavior, and immutable date. It even adds a policy-level restriction against rewriting published history. It does not address error cases or return values, but the schema and annotations already supply the required/optional shape, so nothing critical for correct invocation 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?

The input schema already documents all three parameters with 100% coverage, including the optionality of body and the empty-string behavior of version. The description reinforces this with 'Anything you leave out is left exactly as it was' and maps body/version to notes/version label, but it does not materially add meaning beyond the schema's own parameter descriptions.

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 opens with 'Edits one changelog entry on a game you own,' identifying the verb, resource, and ownership scope clearly. It further narrows the action to 'its notes, its version label, or both,' which distinguishes it from sibling tools like add_changelog_entry and delete_changelog_entry without requiring the agent 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 gives explicit intended use: 'Use it to correct a mistake, not to rewrite history' and explains that the entry keeps its original date. This provides clear when-to-use and when-not-to-use context, though it does not explicitly name sibling alternatives such as add_changelog_entry or delete_changelog_entry, so it falls just short of full routing guidance.

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