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

Annotations already declare readOnly, idempotent, closed-world, non-destructive, so the safety profile is covered. The description adds genuinely useful behavioral context beyond that: output is one short page, and "what the server keeps (nothing)" discloses statelessness, which affects how an agent should reason about persistence.

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?

A single sentence, front-loaded with the verb, with the content list and the usage cue packed in without filler. Every clause carries information an agent would otherwise have to discover by calling the 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 no parameters and no output schema, the description carries the full burden and does so: it says what the page covers, how long it is, and that nothing is persisted. Nothing an agent needs in order to decide to call this first is missing.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate; the baseline for a parameterless tool applies. No misleading parameter language is present.

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?

"Explain this hosted ArchLang server in one short page" gives a specific verb and resource, and the enumerated contents (authoring loop, size cap, unavailable features, image URLs, statelessness) make the scope concrete. It does not explicitly distinguish itself from the sibling "describe" tool, so an agent could briefly wonder whether describe serves a similar role.

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?

"Call it first when unsure" is an explicit, actionable usage directive that tells the agent when to reach for this tool. There is no statement of when NOT to use it and no named alternative for the cases it does not cover, keeping it short of a 5.

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