compare_snapshots

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

With no annotations, the description must carry the full burden. It discloses the return type (line counts and sample changes) but does not mention destructive behavior, authentication needs, rate limits, or size limits implied by the max_chars parameter.

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 a single concise sentence that conveys the core purpose and output. It could be slightly improved by adding structure (e.g., listing parameters), but it is not verbose.

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?

No output schema is provided, so the description must explain the return value. It does so minimally ('line counts and sample changes'), but lacks detail on the structure of sample changes, error handling, or behavior with invalid inputs. Adequate but incomplete.

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 only 25% (only date_a has a description). The description adds minimal context ('of the same URL') but does not detail the format of date_a and date_b, nor explain the purpose of max_chars. The description fails to compensate for the low schema coverage.

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 the tool compares two Wayback snapshots by extracted text, specifying the output (added/removed line counts and sample changes). It distinguishes itself from sibling tools like list_snapshots and fetch_archived_text.

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 implies usage for comparing two snapshots of the same URL but does not explicitly state when to use this tool versus alternatives (e.g., fetch_archived_text for single snapshot). No exclusions or alternatives are mentioned.

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