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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. The description still adds real behavior: full retention of every run, diffing by finding code rather than message, and URL-based matching for runs that predate the watch feature. It omits auth expectations and pagination behavior across the limit window, keeping it short of a 5.

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 the resource and its meaning, then layers in the change semantics. Dense but every clause carries information; the parenthetical field list is mildly heavy but not redundant.

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?

With no output schema, the description carries the return-value burden and does so: score, counts, and a `change` object with point delta plus `broke`/`fixed` findings. What is missing is a note on the guest_token credential and how limit affects the returned series.

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 67% (guest_token is undocumented), and the description never mentions id, limit or guest_token directly. It only implicitly frames "the tab" that id must reference. Baseline 3 is appropriate for mid-level coverage where the schema does most of the work.

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 concrete verb and resource: reading a tab's previous runs and the diff between consecutive runs. The described payload (score, counts, appeared/disappeared findings) is specific enough that an agent can distinguish it from list_tabs, run_tab, watch_tab and get_audit without opening any schema.

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?

"this is where you read the series" points at when to use it, and "Every run has always been kept" implies historical coverage. However there is no explicit contrast with siblings (run_tab to produce a run, watch_tab for ongoing, get_audit for a single audit), so the routing guidance stays implied rather than stated.

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