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

Annotations already cover readOnlyHint, openWorldHint, and idempotentHint. The description adds useful behavioral detail beyond that: reads robots.txt, follows sitemaps and sitemap indexes, returns URLs with last-modified dates newest first, optionally filters by path, and returns robots rules. No contradiction with annotations, and it discloses meaningful output behavior.

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 front-loaded with the core behavior, then usage, then pricing. It is mostly efficient, though the price is stated twice (title and description) and a few phrases could be tightened. Every sentence broadly earns its place for a paid tool.

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 an output schema present and rich annotations, the description supplies all the context an agent needs: purpose, usage, return behavior, pricing, and trial status. Nothing critical is missing for correct invocation.

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 the schema already documents all three parameters. The description repeats the path filter example ('/blog/') but adds no new parameter semantics beyond the schema and does not mention the limit parameter. 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?

The description states a specific verb and resource: reads robots.txt, follows sitemaps, and returns URLs with last-modified dates. It is clearly different from a generic crawl, but it does not explicitly name the sibling crawl tool as the alternative, which keeps it from a 5.

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?

It gives a clear context for use: 'Plan a crawl or spot new pages cheaply.' This is more than implied usage, but no when-not or alternative tools are named, so it does not reach the 5 level.

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