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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), yet the description adds substantial behavior beyond them: removals are suppressed when crawl coverage drops under 90% so a blocked crawl is never reported as site loss, the first run is a baseline with nothing to compare, and results are capped at 200 entries per list. These are non-obvious edge-case semantics an agent must know.

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?

Dense but front-loaded: the core operation leads, then the returned lists, then routing to siblings, then edge-case caveats. Every clause carries information (limits, suppression rule, baseline rule, cost) with no 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?

With no output schema, the description must characterize the response, and it does: entry types, per-list cap of 200, coverage, and the run-provenance caveat. Combined with the baseline and suppression rules, an agent has everything needed to call and interpret it.

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 run_id's null default and provenance. The description restates the run_id fallback ('last finished run unless run_id is given'), which adds emphasis but little new syntax or format information. Baseline 3 applies.

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 specific verb and resource ('report what changed in a project run') and enumerates exactly what is reported: pages added/modified/removed, head-field changes, and run coverage. It distinguishes itself from list_pages and get_page by name, so an agent can pick it 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?

Gives the direct use case ('answer what changed on the site') and explicitly routes to alternatives with their conditions: list_pages shows every page regardless of change, get_page shows one page's text and versions. That is when-to-use plus when-not-to-use in one sentence.

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