list_regressions

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

No annotations are provided, so the description must fully disclose behavior. It mentions it reads data (regressions) but lacks specifics: no mention of data freshness, pagination, rate limits, or whether it's read-only. The return format is only vaguely implied ('when and by how much').

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?

Two sentences, front-loaded with the primary action. Every sentence serves a clear purpose. No redundant or filler content.

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 exists, yet the description only vaguely mentions showing 'when and by how much' the site degraded. It does not specify what the output contains (e.g., list of snapshots, dates, scores). Also, with 4 optional parameters, it doesn't clarify that either url or site_id is likely needed – it treats them as optional, but the phrase 'for a site' suggests one is required.

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 coverage is 100%, so baseline is 3. The description does not add parameter-level details beyond the schema; it only reinforces the concept of regression detection. No extra semantic value provided.

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 uses a specific verb ('Show') and resource ('recent performance regressions for a site'), and defines what regressions are (consecutive scans with significant drop). This clearly distinguishes it from sibling tools like get_site_metrics or compare_snapshots.

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 when identifying regressions ('Helps identify when and by how much the site degraded'), but it does not explicitly state prerequisites (e.g., need for historical scans) or compare with alternatives. No guidance on when not to use this tool.

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