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

Annotations already declare read-only/idempotent/non-destructive, and the description adds genuinely new behavior: the 1 MB cap, the explicit TRUNCATED marker with full size, the consequence of republishing a truncated page, and a prompt-injection warning about treating HTML as data. That is exactly the extra context annotations cannot express.

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?

Three sentences, zero filler, and the primary capability is front-loaded before the size caveat and the safety note. Each sentence carries a distinct, actionable fact.

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 supplies the return format (HTML or TRUNCATED with full size), the size limit, and the safe follow-up action. An agent has everything needed to call it and handle both normal and truncated responses correctly.

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% and the single "site" parameter is already documented with id/name examples and a pointer to list_sites. The description adds no further parameter meaning, so the baseline of 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 ("Returns the current HTML code of one site") plus the size envelope (up to 1 MB) and the intended use ("so you can edit it"). This clearly separates it from get_site_stats (metrics, not content) and update_site (the write counterpart).

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 a clear use context (fetching HTML in order to edit) and an explicit exclusion — do not send a TRUNCATED response back via update_site. It names the alternative tool, but doesn't state the read-before-write sequencing or contrast against get_site_stats/list_versions, so it falls just short of a full when/when-not map.

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