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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so safety and repeatability are covered without the description. The description adds useful filter semantics (substring matching, with a concrete domain example) but says nothing about pagination defaults, result ordering, or what a listing entry contains.

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?

One front-loaded sentence that leads with the action and then the optional filters; nothing is padding. The misspelled resource name wastes a few tokens on confusion rather than clarity.

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?

For a read-only list tool whose safety profile is fully covered by annotations and which has no output schema to explain, the description covers the distinguishing filter behavior well. The remaining gap is pagination — paging through results is an operational detail the agent must know and it is documented nowhere.

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 0%, so the description must carry the burden. It does add real meaning for three of five parameters — distinguishing CNAME label matching from full-domain matching and giving a `blog.example.com` example — but `page` and `per_page` (with defaults 1 and 50) are never mentioned, leaving pagination undocumented in both the schema and the description.

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 (list websites) plus the three filters it supports, so an agent can tell it apart from get_website or the ads/insights siblings. The garbled resource string 'seliee_websites' slightly muddies what is being listed, and it never says explicitly that it differs from get_website.

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?

Usage is only implied: 'optionally filtered by' tells the agent filters exist but not when to apply which, nor when to prefer get_website for a single record or ads_insights_websites for advertising data. No exclusions or prerequisites are stated, though the low-risk read nature makes exhaustive guidance less critical.

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