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

Annotations already cover the safety profile (readOnly, idempotent, closed-world), but the description goes further: it discloses that snapshots hold content hashes not bodies, so schema diffs are not returned directly and `detail` exposes release-asset locations instead, and that a missing month yields an error naming available months rather than a misleading empty diff.

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 purpose, then usage, then caveats, with each paragraph carrying distinct information. It is somewhat long for two parameters, but the added sentences cover hash-vs-body and error semantics that are not 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?

For a tool with no output schema and non-obvious semantics, the description explains the return content (changed tools plus kind of change), the escape hatch for exact diffs, and the failure mode for missing snapshots. An agent has enough to call it and interpret the result correctly.

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 both parameters are already documented, including the `since` omission behavior. The description reinforces 'exact name' and 'the month you name' but adds little syntax or format detail beyond what the schema provides; baseline 3 is appropriate.

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 precise verb and resource: report which tools were added, removed, or changed (description/input schema/output schema) between a named month and the latest snapshot. This is clearly distinguishable from the sibling liveness_check, which the description itself contrasts against.

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?

Gives explicit triggers ('server worked before and is behaving differently now', 'a prompt or integration ... has started failing', 'before trusting a tool description you cached') and explicitly contrasts itself with a liveness check: liveness says it answers today, this says whether it is still the same server.

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